Associations between pregnancy glucose measurements and risk of preterm birth: a retrospective cohort study of commercially insured women in the United States from 2003-2021

Abstract

Purpose:

To investigate associations between glucose measurements during pregnancy and risk of preterm birth (PTB).

Methods:

Retrospective cohort study of commercially insured women with singleton live births in the United States from 2003-2021 using longitudinal medical claims, socioeconomic data, and eight glucose results from different types of fasting and post-load tests performed between 24-28 weeks of gestation for gestational diabetes screening. Risk ratios of PTB (<37 weeks) were estimated via Poisson regression for z-standardized glucose measures. Non-linear relationships for continuous glucose measures were examined via generalized additive models.

Results:

Elevations in all eight glucose measures were associated with increased risk (adjusted risk ratio point estimates: 1.05-1.19) of PTB for 196,377 women with non-fasting 50-gram glucose challenge test (one glucose result), 31,522 women with complete 100-gram, 3-hour fasting oral glucose tolerance test (OGTT) results (four glucose results), and 10,978 women with complete 75-gram, 2-hour fasting OGTT results (three glucose results). Associations were consistent after adjusting for and stratifying by sociodemographic and clinical factors. Substantial non-linear relationships (U-, J-, and S-shaped) were observed between several glucose measurements and PTB.

Conclusions:

Elevations in various glucose measures were linearly and non-linearly associated with increased risk of PTB, even before diagnostic thresholds for gestational diabetes.

Introduction:

Preterm birth (i.e., gestation <37 weeks) remains a leading cause of death for children under five years old, affecting 1 in 10 babies in the United States [1, 2]. Long-term effects of preterm birth span from delayed childhood neurodevelopment to increased adulthood mortality [3, 4]. The most recent estimate of societal costs associated with preterm births delivered in 2016 was $25.2 billion in the United States, including delivery care, medical care of preterm infants, educational interventions, and productivity losses due to disabilities among adults [5].

Diabetes mellitus is a well-documented risk factor for preterm birth and other adverse pregnancy outcomes [6–9]. Clinical guidelines have been established to screen for gestational diabetes [10], and lifestyle interventions have been shown to reduce both levels of maternal blood glucose and risks of preterm birth [11]. However, several studies report that preterm birth risk may increase before maternal glucose thresholds for the diagnosis of gestational diabetes are reached [12–15]. The studies, however, are relatively small and have been unable to explore pertinent confounding variables [11, 16]. In addition, while most studies have examined associations between glucose levels and pregnancy outcomes only via linear relationships and concluded graded linear relationships with no clear thresholds, there is some evidence that such associations could have flattening trends at increased glucose levels, suggesting potential non-linearity [17].

The potential biological link between glucose levels and preterm birth may involve inflammatory pathways that impact the placenta and vascularization [18–20]. In murine and ex vivo human placental cell studies, preterm birth has been linked with inflammation pathways such as COX-2 and IL-6 [21–23], NLRP3 inflammasome [24–27], and TNF-alpha [28]. Such inflammatory mediators have been associated with increased plasma glucose levels in pregnant women without overt diabetes [29]. Studies on placental tissue have indicated elevated inflammatory mediators among women with hyperglycemia without overt diabetes [30, 31]. Therefore, elevated blood glucose may further exacerbate already elevated states of inflammation during pregnancy, resulting in premature delivery. As rates of diabetes and preterm births continue to rise [32], and as the precise etiology of preterm birth is still unknown [33], a more nuanced approach will be critical to study the relationship between glucose levels and preterm birth.

The current study aimed to extend our understanding by investigating a national commercial claims database with information on both individual and area level socioeconomic factors. We hypothesized that increased levels of gestational blood glucose are continuously associated with increased risks of preterm birth that begin to rise before diagnostic thresholds for diabetes, even after controlling for sociodemographic and clinical covariates.

Methods:

This retrospective cohort study used the Clinformatics^® Data Mart Database (CDM), which is a de-identified database derived from a large adjudicated commercial claims data warehouse. We used the “CDM SES” and “CDM ZIP5” versions [34, 35], which contain longitudinal medical claims, laboratory measurements, and commercial insurance enrollee information from 2003 to 2021 across the United States. The CDM SES and ZIP5 versions contain information on enrollees’ education level and race/ethnicity imputed by the dataset provider along with 5-digit ZIP codes, respectively. These versions cover the same population but are not cross-linkable to preserve privacy. The Stanford University Institutional Review Board approved this study.

The target study population was birthing people [36] (referred to as women to reflect how data were collected) between ages 13 and 55 with continuous enrollment, defined as enrollment in commercial health insurance from at least 90 days before their estimated last menstrual period date through their delivery date (date estimation methods are described below). All codes were derived from previous studies that used similar claims data (Appendix A) [37–41]. International Classification of Diseases (ICD)-9 codes were converted to ICD-10 via general equivalence mappings as necessary [42].

Defining Pregnancy Episodes

We identified pregnancy episodes using ICD codes from Sarayani et. al for live births, stillbirths, abortions, and ectopic pregnancies to indicate the end of an episode (Table A.1) [38]. Claims within 30 days of another were considered the same pregnancy episode [43]. Delivery date was considered the first date of claims belonging to each pregnancy end episode. Only the first episode identified in the database for each patient was used to capture women without prior obstetric history in the database. Our study was limited to live births and among those only singleton births (ICD-9: V27.0; ICD-10: Z37.0) were considered because multiple births have differing adverse outcome risks [44].

Estimating Gestational Ages

The outcome was preterm birth, defined as delivery before 37 weeks of gestation. Gestational ages were estimated using a hierarchical method synthesized from previous studies on pregnancy outcomes using claims datasets. Following similar methodology as Marić et. al, we first assigned gestational ages via ICD codes (Table A.2). Among deliveries without gestational age codes, we linked infant records with gestational age codes to maternal records via patient plan number. Last menstrual period dates were approximated by subtracting gestational ages from delivery dates.

For remaining pregnancies, we refined the methodology by Marić et. al and searched all claims occurring within 43 weeks (301 days) before the delivery date to capture a maximum potential gestational period. Following similar methodology as Matcho et. al [37], we estimated last menstrual period dates by subtracting a predetermined number of days from the date of claims containing Current Procedural Terminology (CPT) procedure and ICD diagnosis codes typically administered at narrow windows during pregnancy. If a code with higher priority was identified, codes with lower priority were not searched. In order of priority, these codes and days were:

1. Nuchal translucency ultrasound (CPT: 76813), minus 89 days

2. Alpha fetoprotein test (CPT: 82105), minus 123 days

3. Amenorrhea diagnosis (ICD-9: 626.0; ICD-10: N91.2), minus 55 days

4. Urine pregnancy test (CPT: 81025), minus 55 days

Gestational age was calculated as the difference between estimated last menstrual period and delivery dates. Finally, pregnancies without any codes described above were assigned a gestational age of 39 weeks consistent with previous research [38].

Identifying Glucose Measurements

The exposure variables were fasting and post-load blood glucose levels performed between 24 and 28 weeks of gestation as part of gestational diabetes screening. The 1-hour glucose tolerance test (glucose challenge test) is a screening test for gestational diabetes, while the 3-hour and 2-hour oral glucose tolerance tests are considered diagnostic. The CDM datasets contain results for tests performed within their select laboratory networks. Using Logical Observation Identifiers Names and Codes (LOINC^®) system codes [45], we identified results from the two-step approach (1-hour screening test followed by 3-hour diagnostic test if positive) recommended by the American College of Obstetricians & Gynecologists (ACOG) and the one-step approach (2-hour diagnostic test) recommended by the American Diabetes Association (ADA) and the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) [46, 47]. Preferences for approaches vary by clinical practice, with the ACOG approach being most common in the United States [48].

From these two approaches, there are eight possible types of glucose measurements. In the ACOG approach, if a patient receives an abnormal value for the non-fasting 50-gram glucose challenge test (i.e., the 1-hour glucose screen, for which only one glucose level is resulted one-hour post-glucose ingestion; LOINC: 1504-0), then the fasting 100-gram 3-hour oral glucose tolerance test is done (i.e., four glucose levels are resulted: one fasting level, then one at each of the three hours post-glucose ingestion; LOINC: 1558-6, 1501-6, 1514-9, and 1530-5, respectively). The ADA approach includes the fasting 75-gram 2-hour oral glucose tolerance test (i.e., three glucose levels are resulted: one fasting level, then one at each of the two hours post-glucose ingestion; LOINC: 1558-6, 1507-3, and 1518-0, respectively).

In case of multiple measurements for a given result type, the last measurement was used to reflect possible clinical decisions to recheck glucose measurements. To investigate plausible glucose values, we restricted fasting plasma glucose values to ≥55 mg/dL to exclude hypoglycemia and ≤250 mg/dL to exclude diabetic ketoacidosis [49, 50]. For other glucose results, we restricted values to those between the initial 0.05th and 99.5th percentile of each result type. We also examined z-score standardized variables to enhance comparability across different glucose tests. The average ± standard deviation (SD) in mg/dL used for z-score standardization were: ACOG 50-g screen (118.2 ± 29.2), ACOG 100-g fasting (80.8 ± 10.0), ACOG 100-g 1-hour (160.6 ± 30.3), ACOG 100-g 2-hour (139.3 ± 29.2), ACOG 100-g 3-hour (108.0 ± 28.4), ADA 75-g fasting (80.2 ± 9.6), ADA 75-g 1-hour (147.1 ± 33.7), and ADA 75-g 2-hour (128.2 ± 31.5).

Joining Covariate Variables

We searched claims ranging from the estimated last menstrual period date to the last date of hospitalization to define binary (yes vs. no) variables previously identified as important comorbidities and complications [39]. These variables were based on ICD codes (Table A.3) and included: gestational diabetes, type 1 and 2 diabetes, obesity, infection, mental illness, substance use, cervical shortening, premature rupture of membranes, preeclampsia, and poor fetal growth. We also defined binary variables on whether prenatal care was initiated within 5 months of gestation [51, 52].

Women without gestational diabetes ICD codes but with complete oral glucose tolerance test results were considered to have gestational diabetes if they met diagnostic criteria: for those with the 100-gram 3-hour ACOG test were according to Carpenter-Coustan criteria (≥95, 180, 155, and 140 mg/dL for fasting, 1-hour, 2-hour, and 3-hour plasma glucose concentrations, respectively) and for those with the 75-gram 2-hour ADA test were according to IADPSG criteria (≥92, 180, and 153 mg/dL for fasting, 1-hour, and 2-hour plasma glucose concentrations, respectively).

For the SES dataset version, we included maternal education level and race/ethnicity provided by CDM. For the ZIP5 dataset version, we linked the Area Deprivation Index via 5-digit ZIP code of maternal residence. The Area Deprivation Index is a measure that captures neighborhood-level disadvantage by incorporating multiple socioeconomic domains including housing and poverty and has been used in previous studies on social determinants of health [53]. If multiple ZIP codes were present to ensure data privacy, we calculated weighted averages of Area Deprivation Index by ZIP code populations from the 2010 US Census.

Preterm Birth Phenotypes

Spontaneous or medically indicated phenotypes were defined with ICD codes from previous studies (Table A.4) [40, 41]. A preterm birth was considered spontaneous if there was an ICD diagnosis code for premature rupture of membranes or preterm labor [40]. Among those without spontaneous phenotype codes, a preterm birth was considered medically indicated if there was an ICD procedure code for induction or caesarean section [41]. Preterm births that could not be categorized as above were considered unclassified.

Remaining Inclusion/Exclusion Criteria

The flowchart for cohort building is depicted in Figure B.1. Estimated gestational ages were required to range from 24 to 42 weeks. Women with claims codes related to in vitro fertilization, previous preterm birth, poor obstetric history (e.g., previous postpartum hemorrhage, forceps delivery, etc.), or diabetes (type 1 or 2) were excluded.

Statistical Analyses

We calculated summary statistics of sociodemographic and clinical characteristics. We used Poisson regression to estimate risk ratio (RR) with 95% confidence interval (CI) of preterm birth for an increase of one SD from the mean for each glucose measurement, a similar approach used in other studies [15, 54]. We adjusted for the following aforementioned binary-defined variables: obesity, infection, mental illness, substance use, cervical shortening, and initiation of prenatal care within 5 months of gestation, as well as categorical variables for educational level, race/ethnicity, quartile of Area Deprivation Index, and US Census region in applicable dataset versions. Maternal age (<25, 25-29, 30-34, and ≥35 years) was included as a categorical variable. Women with unknown education and race/ethnicity were excluded during model adjustment.

To assess for effect modification, we stratified analyses by: preterm birth phenotype, gestational diabetes status, preeclampsia status, maternal age, education, race/ethnicity, Area Deprivation Index quartile, and US Census region. We also assessed narrower definitions of preterm birth (i.e., early <34 weeks vs. late 34 to 36 weeks), with the reference group being gestational ages 37 to 42 weeks. To assess for non-linear relationships between glucose measures and risk of preterm birth, we used generalized additive models to regress the outcome of preterm birth on smoothed, continuous measures of glucose and adjusted for the same covariate variables using the CDM ZIP5 version [55]. The advantages generalized additive models include (1) flexibility, because unlike linear or polynomial models, they do not require a priori specifications for the model shape and instead identifies the model shape by optimizing goodness of fit and smoothness; and (2) interpretability, because unlike advanced machine learning methods, the results contain intuitive outputs regarding modeled parameters to reveal insights on the possible underlying relationship between parameters [56]. Generalized additive models have been used in occupational and environmental epidemiology given that scientific phenomena are often nonlinear [57, 58]. We plotted graphs for generalized additive models from the 1st to 99th percentile. All analyses were performed using R [59].

Results:

Of the initial 211,005 women in the CDM SES version with at least one glucose measurement, 196,377 had the non-fasting glucose challenge test recommended by ACOG. Among the 58,342 who exceeded the 135 mg/dL threshold for the glucose challenge test, 31,522 had complete measurements for the fasting 3-hour oral glucose tolerance test recommended by ACOG. Additionally, 10,978 women had complete measurements for the fasting 2-hour oral glucose tolerance test recommended by ADA.

Summary statistics are shown in Table 1. Gestational diabetes prevalence was 15.4% among women with continuous enrollment, 17.1% among women who received the ACOG non-fasting glucose challenge test (screening), 56.8% among women with complete diagnostic ACOG 3-hour oral glucose tolerance test results, and 44.5% among women with complete diagnostic ADA 2-hour oral glucose tolerance test results. The CDM ZIP5 version had similar sample sizes and summary statistics (Table B.1). Distributions of various glucose measures are summarized in Table B.2.

Table 1.

Summary Statistics for Pregnancy Cohorts

Characteristics (CDM SES version)	Continuous Enrollment n = 817,451	ACOG Screen (Non-Fasting) n = 196,377	Complete ACOG OGTT n = 31,522	Complete ADA OGTT n = 10,978
Maternal Age (years)	(%)	(%)	(%)	(%)
≤24	10.1	7.8	4.1	6.1
25-29	24.0	22.5	18.8	19.9
30-34	37.1	39.4	40.4	40.6
≥35	28.8	30.4	36.7	33.4
Clinical Covariates
Prenatal Care within 5 Months	82.9	81.7	81.6	82.2
Gestational Diabetes	15.4	17.1	56.8	44.5
Obesity	10.6	12.5	17.5	16.4
Infection	31.2	32.9	32.5	33.9
Mental Illness	10.7	10.5	10.9	9.8
Substance Use	4.1	3.3	3.5	3.3
Pregnancy Complications
Cervical Shortening	1.0	1.3	1.7	1.8
Premature Rupture of Membranes	7.5	7.5	8.1	7.4
Preeclampsia	15.3	15.6	19.4	17.2
Poor Fetal Growth	14.8	15.0	14.2	14.9
Gestational Age
24-31 weeks	0.8	0.3	0.2	0.4
32-33 weeks	0.5	0.4	0.5	0.4
34-36 weeks	8.6	7.6	8.8	8.8
37-42 weeks	90.1	91.8	90.5	90.4
Preterm birth type (<37 weeks)
Spontaneous	6.7	5.5	6.5	6.1
Medically indicated	2.0	1.8	2.0	2.4
Unclassified	1.3	0.9	1.0	1.1
Education
Less than 12th Grade	0.6	0.5	0.5	1.0
High School Diploma	20.6	18.1	17.5	20.0
Less than Bachelor Degree	53.1	52.9	53.2	53.8
Bachelor Degree or Higher	25.4	28.2	28.6	25.1
Unknown	0.3	0.2	0.2	0.2
Race/Ethnicity
White (Non-Hispanic)	66.0	62.0	56.6	52.8
Black (Non-Hispanic)	9.5	10.1	9.3	8.3
Hispanic (all)	14.3	16.9	17.7	22.6
Asian	7.8	8.8	14.2	14.3
Unknown	2.5	2.2	2.2	2.0
Characteristics (CDM ZIP5 version)	Continuous Enrollment n = 886,333	ACOG Screen (Non-Fasting) n = 210,274	Complete ACOG OGTT n = 33,603	Complete ADA OGTT n = 11,603
US Census Region	(%)	(%)	(%)	(%)
West	20.9	19.4	20.3	39.7
Midwest	26.0	11.5	9.0	10.3
South	43.3	59.9	59.7	45.3
Northeast	9.9	9.2	11.1	4.7
Area Deprivation Index Quartile
(least deprivation) Quartile 1	46.1	49.3	50.7	45.7
Quartile 2	21.4	20.4	20.3	20.1
Quartile 3	17.0	15.7	14.9	16.7
(most deprivation) Quartile 4	15.5	14.6	14.1	17.5

ACOG = American College of Obstetricians & Gynecologists; ADA = American Diabetes Association; OGTT = oral glucose tolerance test

A one SD Increase of glucose for each measurement type was associated with increased risk of preterm birth, with RR estimates from Poisson regression analyses shown in Table 2. For example, there was an 18% increase in risk of preterm birth for a one SD increase of glucose for the ACOG non-fasting glucose challenge test (RR: 1.18, 95% CI: 1.16 to 1.20). Estimates using the CDM ZIP5 version did not differ considerably from estimates using the CDM SES version (Table B.3). Adjusted estimates were either slightly attenuated or the same as compared to unadjusted estimates.

Table 2.

Unadjusted and Adjusted Poisson Regression Results for Preterm Birth with Stratification by Preterm Birth Phenotype and Disaggregation by Early vs. Late Preterm Birth (CDM SES Version)

Glucose Measurement	Overall PTB < 37 weeks Unadjusted RR (95%CI)	Overall PTB < 37 weeks aRR (95%CI)	Spontaneous PTB < 37 weeks aRR (95%CI)	Medically Indicated PTB < 37 weeks aRR (95%CI)	Early PTB < 34 weeks* aRR (95%CI)	Late PTB 34-36 weeks* aRR (95%CI)
ACOG, 50-g, Non-Fasting Screen	1.18 (1.16, 1.20)	1.18 (1.16, 1.20)	1.19 (1.16, 1.21)	1.23 (1.19, 1.28)	1.26 (1.19, 1.33)	1.17 (1.15, 1.19)
ACOG, 100-g, Fasting	1.09 (1.06, 1.13)	1.07 (1.04, 1.11)	1.11 (1.07, 1.15)	1.07 (0.99, 1.15)	0.98 (0.86, 1.12)	1.08 (1.05, 1.12)
ACOG, 100-g, 1-hour post-load	1.13 (1.08, 1.17)	1.13 (1.09, 1.17)	1.16 (1.11, 1.22)	1.14 (1.05, 1.24)	1.06 (0.92, 1.22)	1.13 (1.09, 1.18)
ACOG, 100-g, 2-hour post-load	1.15 (1.11, 1.19)	1.15 (1.11, 1.19)	1.18 (1.13, 1.24)	1.12 (1.03, 1.21)	1.10 (0.96, 1.25)	1.15 (1.11, 1.19)
ACOG, 100-g, 3-hour post-load	1.11 (1.07, 1.15)	1.11 (1.07, 1.15)	1.14 (1.09, 1.19)	1.05 (0.97, 1.14)	1.06 (0.92, 1.21)	1.11 (1.07, 1.15)
ADA, 75-g, Fasting	1.07 (1.01, 1.13)	1.05 (0.99, 1.12)	1.07 (0.99, 1.16)	1.03 (0.92, 1.17)	0.99 (0.79, 1.25)	1.07 (1.00, 1.14)
ADA, 75-g, 1-hour post-load	1.16 (1.09, 1.23)	1.15 (1.08, 1.23)	1.17 (1.08, 1.27)	1.11 (0.98, 1.26)	1.18 (0.95, 1.47)	1.16 (1.08, 1.24)
ADA, 75-g, 2-hour post-load	1.20 (1.13, 1.27)	1.19 (1.12, 1.27)	1.25 (1.16, 1.34)	1.18 (1.05, 1.34)	1.10 (0.89, 1.36)	1.21 (1.14, 1.29)

aRR = adjusted risk ratio; CI = confidence interval; PTB = preterm birth; ACOG = American College of Obstetricians and Gynecologists; ADA = American Diabetes Association;

RR are calculated for an increase of 1 SD from the mean for each glucose measurement.

^*Reference group is births with gestational age 37-42 weeks. Models were adjusted for maternal age, education level, race/ethnicity, obesity, infection, mental illness, substance use, cervical shortening, and prenatal care. The CDM SES dataset version was used.

The associations remained largely consistent with overlapping confidence intervals when stratified by phenotype (spontaneous vs. medically indicated), gestational diabetes status, and preeclampsia status (Table 2; Tables B.4–5). There were no substantive differences in RR estimates across stratifications by Area Deprivation Index quartile, education, race/ethnicity, or US Census region (Table 3; Tables B.6–9). We did not observe substantive differences between narrower phenotypes of early vs. late preterm birth (Table 2).

Table 3.

Adjusted Poisson Regression Results for Preterm Birth Stratified by Area Deprivation Index Quartile

Glucose Measurement	Overall aRR (95%CI)	Quartile 1 aRR (95%CI)	Quartile 2 aRR (95%CI)	Quartile 3 aRR (95%CI)	Quartile 4 aRR (95%CI)
ACOG, 50-g, Non-Fasting Screen	1.18 (1.16, 1.20)	1.18 (1.16, 1.21)	1.19 (1.15, 1.23)	1.17 (1.13, 1.21)	1.17 (1.13, 1.22)
ACOG, 100-g, Fasting	1.07 (1.03, 1.10)	1.08 (1.03, 1.13)	1.05 (0.98, 1.13)	1.01 (0.92, 1.10)	1.11 (1.03, 1.18)
ACOG, 100-g, 1-hour post-load	1.12 (1.08, 1.16)	1.12 (1.06, 1.18)	1.12 (1.04, 1.21)	1.14 (1.04, 1.25)	1.12 (1.02, 1.22)
ACOG, 100-g, 2-hour post-load	1.15 (1.11, 1.19)	1.18 (1.12, 1.24)	1.08 (1.01, 1.17)	1.16 (1.06, 1.26)	1.14 (1.05, 1.23)
ACOG, 100-g, 3-hour post-load	1.10 (1.06, 1.14)	1.10 (1.05, 1.16)	1.05 (0.98, 1.13)	1.16 (1.06, 1.27)	1.09 (1.00, 1.19)
ADA, 75-g, Fasting	1.05 (0.99, 1.11)	1.08 (0.97, 1.20)	1.16 (1.03, 1.30)	0.96 (0.83, 1.11)	0.93 (0.82, 1.07)
ADA, 75-g, 1-hour post-load	1.13 (1.06, 1.20)	1.23 (1.12, 1.36)	1.13 (1.00, 1.28)	1.04 (0.89, 1.21)	1.02 (0.88, 1.17)
ADA, 75-g, 2-hour post-load	1.16 (1.09, 1.23)	1.21 (1.11, 1.33)	1.14 (1.01, 1.29)	1.11 (0.96, 1.28)	1.11 (0.96, 1.28)

aRR = adjusted risk ratio; ACOG = American College of Obstetricians and Gynecologists; ADA = American Diabetes Association;

RR are calculated for an increase of 1 SD from the mean for each glucose measurement. Models were adjusted in a similar manner described in Table 2, except with the replacement of maternal education and race/ethnicity with US Census region. Quartile 1 indicates the least disadvantaged neighborhoods, while Quartile 4 indicates the most disadvantaged neighborhoods. The CDM ZIP5 dataset version was used.

Figures 1–3 show results for generalized additive model analyses. The ACOG non-fasting glucose challenge test had a relatively linear association for preterm birth (Figure 1). For the ACOG 3-hour oral glucose tolerance test, the 1-hour and 2-hour measurements were approximately linear, whereas the fasting measurement displayed an S-shaped curve and the 3-hour measurement displayed a J-shaped curve (Figure 2). For the ADA 2-hour oral glucose tolerance test, the fasting glucose measurement displayed a U-shaped curve, whereas the 1-hour and 2-hour measurements both displayed S-shaped curves (Figure 3). The smoothed terms of glucose level for all models had large chi-squared statistics, with results for approximate significance shown in Table B.10.

Figure 1.

Adjusted Generalized Additive Model for ACOG Non-Fasting 50-gram 1-hour Test

Generalized additive model results were adjusted for maternal age, Area Deprivation Index quartile, US Census region, obesity, infection, mental illness, substance use, cervical shortening, and prenatal care. The dashed line indicates the threshold for abnormal values. The CDM ZIP5 dataset version was used.

Figure 3.

Adjusted Generalized Additive Model for ADA Fasting 75-gram 2-hour Tests

Generalized additive model results were adjusted for maternal age, Area Deprivation Index quartile, US Census region, obesity, infection, mental illness, substance use, cervical shortening, and prenatal care. The dashed lines indicate diagnostic thresholds for abnormal values. The CDM ZIP5 dataset version was used.

Figure 2.

Adjusted Generalized Additive Model for ACOG Fasting 100-gram 3-hour Test Results

Generalized additive model results were adjusted for maternal age, Area Deprivation Index quartile, US Census region, obesity, infection, mental illness, substance use, cervical shortening, and prenatal care. The dashed lines indicate diagnostic thresholds for abnormal values. The CDM ZIP5 dataset version was used.

Discussion:

We observed that increased levels of various measures of gestational blood glucose were associated with increased risks of preterm birth that began to rise before diagnostic thresholds for diabetes, even after adjusting for and stratifying by several sociodemographic and clinical factors. Some measures had stronger associations than others, with variations in linear and non-linear relationships.

Few studies have examined continuous measures of gestational blood glucose. Our results were of similar magnitudes as previously reported linear associations for 1-hour and 2-hour measurements of the ADA 2-hour oral glucose tolerance test [12, 15, 60]. We extend the literature by describing associations for continuous measurements of the ACOG 3-hour oral glucose tolerance test. Confidence intervals for ACOG 3-hour test and ADA 2-hour test measurements generally coincided, but non-linear analyses differed.

Our study is the first to our knowledge that uses generalized additive models to study non-linear relationships between pregnancy glucose measures and preterm birth. The S-shaped and J-shaped curves for fasting and 3-hour measurements of ACOG oral glucose tolerance test, as well as the S-shaped curves for 1-hour and 2-hour measurements of ADA oral glucose tolerance test, suggest that risks of preterm birth increase before current gestational diabetes thresholds. The S-shaped curves for 1-hour and 2-hour measurements of ADA oral glucose tolerance test are similar to the cubic spline model curve of spontaneous preterm birth risk reported by Jensen et. al [13].

The U-shaped curve for fasting plasma glucose suggests that glucose levels nearing hypoglycemia could also increase risk of preterm birth. This is consistent with a study by Tang et. al that reported lower and higher pre-pregnancy fasting plasma glucose level categories were associated with increased risk of preterm birth, but not for continuous fasting glucose measures [20]. The U-shaped pattern reported in our study may explain why Tang et. al, the Hyperglycemia and Adverse Pregnancy Outcomes study, and Shen et. al did not observe linear associations between fasting plasma glucose and preterm birth [12, 60]. Thus, conventional linear methods may not always be suitable for studying these relationships. We believe it is important that our findings of different risk relationships are replicated in other populations before recommending new diagnostic thresholds. With continued debate on gestational diabetes criteria [48, 61, 62], future studies may use methods such as generalized additive models to assess potential cut-offs for different populations and include additional adverse pregnancy outcomes.

Our estimated risk ratios of preterm birth for those with gestational diabetes were similar to those without, suggesting that glucose levels may increase risk of preterm birth independent of actual gestational diabetes. However, we did not observe earlier preterm births to be more strongly associated with higher glucose levels, which might be expected if increasing levels of glucose exacerbated extant inflammatory physiology. While estimates for spontaneous and medically indicated preterm births were similar, additional studies are needed to understand whether those phenotypes share similar pathways. Specific data on body mass index, rather than just the dichotomy we had to employ here of obese vs. not, could be further informative for disentangling the underlying association. That is, body mass index may modify associations between glucose levels and pregnancy outcomes [63]. Future studies should also examine “large for gestational age” birthweights and macrosomia, which may indicate inadequate maternal glucose control and/or increased insulin resistance [64].

In our study samples, each test may capture different populations. For example, the population with the ACOG non-fasting screen includes all pregnancies, whereas the population with the ACOG 3-hour fasting oral glucose tolerance test required abnormal glucose challenge test results. This abnormal result could be a sign of glucose intolerance and metabolic dysfunction without meeting criteria for gestational diabetes [65]. While the ACOG approach is predominant in the United States, different institutions may still choose the ADA/IADPSG 2-hour fasting test if deemed more appropriate for the populations whom they serve [46]. Future studies should investigate determinants of practice variations.

We recognize several limitations to our study. Our study was limited to women enrolled in commercial health insurance, so we could not assess women with Medicaid, which finances about 42% of births in the United States [66]. Because many women were excluded due to lack of continuous insurance enrollment and laboratory data, the potential selection bias could have led to underestimations of the associations between glucose levels and preterm birth because disruptions in insurance coverage could be associated with poor birth outcomes through decreased prenatal care utilization [67], thus resulting in fewer preterm births in this study sample. At the same time, overestimations of the associations could also be possible if women with at-risk pregnancies and knowledge of their risk factors were more likely to stay continuously insured and have available laboratory data.

Even though selection bias may be a limitation, the magnitudes of our effect size estimates were similar to those reported in prospective cohort studies. For example, in a study of 12,889 pregnancies in Southern China, Shen et. al reported a preterm birth odds ratio of 1.21 (95% CI: 1.10, 1.33) for a 1-SD increase in maternal blood glucose from the mean for the 2-hour measurement of the 75-gram ADA oral glucose tolerance test [60]; compare this to the risk ratio of 1.21 (95% CI: 1.12, 1.30) estimated in our study for the same measurement. While we calculated risk ratios in our present study, the prevalence of the outcome preterm birth was relatively low, i.e., less than 10%, and allows for possible approximation of odds ratios as risk ratios [68]. Additionally, we did not include women who received pregnancy glucose tests before 24 weeks, which may have been initiated for women whom their physician has high suspicion for risk of gestational diabetes and/or other pregnancy complications. There is also possible misclassification of birth outcomes and maternal covariates inherent to use of ICD code classifications.

While previously published estimates of annual gestational diabetes prevalence in the U.S. population was 6.0% in 2016 [69], our study population had a prevalence of about 15%. However, a study by Alur-Gupta et. al also used the CDM dataset as in our study and found a similar ICD code-derived overall prevalence of gestational diabetes among women with continuous enrollment of about 13% [70]. In addition, Kasman et. al used the IBM Marketscan Research commercial claims database in a similar manner and reported an overall prevalence of gestational diabetes to be about 16% in their study population [71]. In our study population that received the ACOG screen non-fasting test, the prevalence of gestational diabetes may have been higher at about 17% because that population may have had a higher risk of gestational diabetes as compared to the average population, so they were more likely to receive the screening and be diagnosed.

In addition, individual-level race/ethnicity and education level were variables imputed by the claims dataset provider, rather than being self-reported or registry-based; although, the risk ratio estimates that controlled for individual-level SES in the CDM SES dataset were similar to those that controlled for the Area Deprivation Index in the CDM ZIP5 dataset. Given these limitation, future studies should examine other populations before generalizing findings from commercially insured populations to the overall population.

One major strength of our study is that we leverage a database linkage that covers diverse geography in the United States and captures the entire course of pregnancy through longitudinal claims data. While we were unable to conduct external validation of the classification algorithms used in our study, we synthesized existing methodology and leveraged the hierarchical algorithm that Matcho et. al validated across four different claims datasets to identify gestational ages for pregnancies without relevant gestational age ICD codes [37].

Conclusions:

Increasing levels of glucose employing pregnancy glucose measures were observed to be associated with increased risk of preterm birth, consistent across numerous individual-level and area-level factors. Glucose levels may lie on the etiology of spontaneous and medically indicated preterm births via inflammatory pathways, and the non-linear relationships observed should be assessed in future studies of glucose and pregnancy outcomes.

List of Abbreviations and Acronyms:

ACOG

American College of Obstetricians and Gynecologists

ADA

American Diabetes Association

aRR

Adjusted Risk Ratio

CI

Confidence Interval

CPT

Current Procedural Terminology

IADPSG

International Association of the Diabetes and Pregnancy Study Groups

ICD

International Classification of Diseases

LOINC

Logical Observation Identifiers Names and Codes

OGTT

Oral Glucose Tolerance Test

PTB

Preterm Birth

RR

Risk Ratio

SD

Standard Deviation

Appendix

Table A.1:

Codes for End of Pregnancy Episode

Code	Code Description	Category	Code Type
V39xx	Liveborn, unspecified whether single, twin, or multiple	Live Birth	ICD-9-CM
V392x	Liveborn, unspecified whether single, twin or multiple, born outside hospital and not hospitalized	Live Birth	ICD-9-CM
V391x	Liveborn, unspecified whether single, twin or multiple, born before admission to hospital	Live Birth	ICD-9-CM
V390x	Other liveborn, unspecified, born in hospital	Live Birth	ICD-9-CM
V3901	Liveborn, unspecified whether single, twin or multiple, born in hospital, delivered by cesarean section	Live Birth	ICD-9-CM
V3900	Liveborn, unspecified whether single, twin or multiple, born in hospital, delivered without mention of cesarean section	Live Birth	ICD-9-CM
V37xx	Other multiple birth (three or more), unspecified whether mates liveborn or stillborn	Live Birth	ICD-9-CM
V372x	Other multiple birth (three or more), unspecified whether mates liveborn or stillborn, born outside of hospital	Live Birth	ICD-9-CM
V371x	Other multiple birth (three or more), unspecified whether mates liveborn or stillborn, born before admission to hospital	Live Birth	ICD-9-CM
V370x	Other multiple, unspecified, born in hospital	Live Birth	ICD-9-CM
V3701	Other multiple birth (three or more), unspecified whether mates liveborn or stillborn, born in hospital, delivered by cesarean section	Live Birth	ICD-9-CM
V3700	Other multiple birth (three or more), unspecified whether mates liveborn or stillborn, born in hospital, delivered without mention of cesarean section	Live Birth	ICD-9-CM
V36xx	Other multiple birth (three or more), mates liveborn and stillborn	Live Birth	ICD-9-CM
V362x	Other multiple birth (three or more), mates liveborn and stillborn, born outside hospital and not hospitalized	Live Birth	ICD-9-CM
V361x	Other multiple birth (three or more), mates liveborn and stillborn, born before admission to hospital	Live Birth	ICD-9-CM
V360x	Other multiple, mates liveborn and stillborn, born in hospital	Live Birth	ICD-9-CM
V3601	Birth (three or more), mates liveborn and stillborn, born in hospital, delivered without mention of cesarean section	Live Birth	ICD-9-CM
V3600	Other multiple birth (three or more), mates liveborn and stillborn, born in hospital, delivered without mention of cesarean section	Live Birth	ICD-9-CM
V35xx	Other multiple birth (three or more), mates all stillborn	Live Birth	ICD-9-CM
V352x	Other multiple birth (three or more), mates all stillborn, born outside of hospital and not hospitalized	Live Birth	ICD-9-CM
V351x	Other multiple birth (three or more), mates all stillborn, born before admission to hospital	Live Birth	ICD-9-CM
V350x	Other multiple, mates all stillborn, born in hospital	Live Birth	ICD-9-CM
V3501	Other multiple birth (three or more), mates all still born, born in hospital, delivered by cesarean section	Live Birth	ICD-9-CM
V3500	Other multiple birth (three or more), mates all still born, born in hospital, delivered without mention of cesarean section	Live Birth	ICD-9-CM
V34xx	Other multiple birth (three or more), mates all liveborn	Live Birth	ICD-9-CM
V342x	Other multiple birth (three or more), mates all liveborn, born outside hospital and not hospitalized	Live Birth	ICD-9-CM
V341x	Other multiple birth (three or more), mates all liveborn, born before admission to hospital	Live Birth	ICD-9-CM
V340x	Other multiple, mates all liveborn, born in hospital	Live Birth	ICD-9-CM
V3400	Other multiple birth (three or more), mates all liveborn, born in hospital, delivered without mention of cesarean section	Live Birth	ICD-9-CM
V33xx	Twin birth, unspecified whether mate liveborn or stillborn	Unclassified Delivery	ICD-9-CM
V332x	Twin birth, unspecified whether mate liveborn or stillborn, born outside hospital and not hospitalized	Unclassified Delivery	ICD-9-CM
V331x	Twin birth, unspecified whether mate liveborn or stillborn, born before admission to hospital	Unclassified Delivery	ICD-9-CM
V330x	Twin, unspecified, born in hospital	Unclassified Delivery	ICD-9-CM
V3300	Twin birth, unspecified whether mate liveborn or stillborn, born in hospital, delivered without mention of cesarean section	Unclassified Delivery	ICD-9-CM
V32xx	Twin birth, mate stillborn	Live Birth	ICD-9-CM
V322x	Twin birth, mate stillborn, born outside hospital and not hospitalized	Live Birth	ICD-9-CM
V321x	Twin birth, mate stillborn, born before admission to hospital	Live Birth	ICD-9-CM
V320x	Twin, mate stillborn, born in hospital	Live Birth	ICD-9-CM
V3201	Twin birth, mate stillborn, born in hospital, delivered by cesarean section	Live Birth	ICD-9-CM
V3200	Twin birth, mate stillborn, born in hospital, delivered without mention of cesarean section	Live Birth	ICD-9-CM
V31xx	Twin birth, mate liveborn	Live Birth	ICD-9-CM
V312x	Twin birth, mate liveborn, born outside hospital and not hospitalized	Live Birth	ICD-9-CM
V311x	Twin birth, mate liveborn, born before admission to hospital	Live Birth	ICD-9-CM
V310x	Twin, mate liveborn, born in hospital	Live Birth	ICD-9-CM
V3101	Twin birth, mate liveborn, born in hospital, delivered by cesarean section	Live Birth	ICD-9-CM
V3100	Twin birth, mate liveborn, born in hospital, delivered without mention of cesarean section	Live Birth	ICD-9-CM
V30xx	Single liveborn	Live Birth	ICD-9-CM
V302x	Single liveborn, born outside hospital and not hospitalized	Live Birth	ICD-9-CM
V301x	Single liveborn, born before admission to hospital	Live Birth	ICD-9-CM
V300x	Single liveborn, born in hospital	Live Birth	ICD-9-CM
V3001	Single liveborn, born in hospital, delivered by cesarean section	Live Birth	ICD-9-CM
V3000	Single liveborn, born in hospital, delivered without mention of cesarean section	Live Birth	ICD-9-CM
V276x	Mother with other multiple birth some liveborn	Mixed delivery	ICD-9-CM
V275x	Mother with other multiple birth all liveborn	Live Birth	ICD-9-CM
V273x	Mother with twins one liveborn and one stillborn	Mixed delivery	ICD-9-CM
V272x	Mother with twins both liveborn	Live Birth	ICD-9-CM
V270x	Mother with single liveborn	Live Birth	ICD-9-CM
650	Normal delivery	Unclassified Delivery	ICD-9-CM
64101	Placenta previa without hemorrhage, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64111	Hemorrhage from placenta previa, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64121	Premature separation of placenta, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64131	Antepartum hemorrhage associated with coagulation defects, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64181	Other antepartum hemorrhage, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64191	Unspecified antepartum hemorrhage, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64201	Benign essential hypertension complicating pregnancy, childbirth, and the puerperium, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64202	Benign essential hypertension, complicating pregnancy, childbirth, and the puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64211	Hypertension secondary to renal disease, complicating pregnancy, childbirth, and the puerperium, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64212	Hypertension secondary to renal disease, complicating pregnancy, childbirth, and the puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64221	Other pre-existing hypertension, complicating pregnancy, childbirth, and the puerperium, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64222	Other pre-existing hypertension, complicating pregnancy, childbirth, and the puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64231	Transient hypertension of pregnancy, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64232	Transient hypertension of pregnancy, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64241	Mild or unspecified pre-eclampsia, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64242	Mild or unspecified pre-eclampsia, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64251	Severe pre-eclampsia, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64252	Severe pre-eclampsia, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64261	Eclampsia, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64262	Eclampsia, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64271	Pre-eclampsia or eclampsia superimposed on pre-existing hypertension, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64272	Pre-eclampsia or eclampsia superimposed on pre-existing hypertension, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64291	Unspecified hypertension complicating pregnancy, childbirth, or the puerperium, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64292	Unspecified hypertension complicating pregnancy, childbirth, or the puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64301	Mild hyperemesis gravidarum, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64311	Hyperemesis gravidarum with metabolic disturbance, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64321	Late vomiting of pregnancy, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64381	Other vomiting complicating pregnancy, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64391	Unspecified vomiting of pregnancy, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64421	Early onset of delivery, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64511	Post term pregnancy, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64521	Prolonged pregnancy, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64601	Papyraceous fetus, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64611	Edema or excessive weight gain in pregnancy, without mention of hypertension, delivered, with or without mention of antepartum complication	Unclassified Delivery	ICD-9-CM
64612	Edema or excessive weight gain in pregnancy, without mention of hypertension, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64621	Unspecified renal disease in pregnancy, without mention of hypertension, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64622	Unspecified renal disease in pregnancy, without mention of hypertension, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64631	Recurrent pregnancy loss, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64641	Peripheral neuritis in pregnancy, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64642	Peripheral neuritis in pregnancy, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64651	Asymptomatic bacteriuria in pregnancy, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64652	Asymptomatic bacteriuria in pregnancy, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64661	Infections of genitourinary tract in pregnancy, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64662	Infections of genitourinary tract in pregnancy, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64671	Liver and biliary tract disorders in pregnancy, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64681	Other specified complications of pregnancy, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64682	Other specified complications of pregnancy, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64691	Unspecified complication of pregnancy, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64701	Syphilis of mother, complicating pregnancy, childbirth, or the puerperium, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64702	Syphilis of mother, complicating pregnancy, childbirth, or the puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64711	Gonorrhea of mother, complicating pregnancy, childbirth, or the puerperium, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64712	Gonorrhea of mother, complicating pregnancy, childbirth, or the puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64731	Tuberculosis of mother, complicating pregnancy, childbirth, or the puerperium, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64732	Tuberculosis of mother, complicating pregnancy, childbirth, or the puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64741	Malaria in the mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64742	Malaria in the mother, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64751	Rubella in the mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64752	Rubella in the mother, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64761	Other viral diseases in the mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64762	Other viral diseases in the mother, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64781	Other specified infectious and parasitic diseases of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64782	Other specified infectious and parasitic diseases of mother, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64791	Unspecified infection or infestation of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64792	Unspecified infection or infestation of mother, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64801	Diabetes mellitus of mother, complicating pregnancy, childbirth, or the puerperium, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64802	Diabetes mellitus of mother, complicating pregnancy, childbirth, or the puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64811	Thyroid dysfunction of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64812	Thyroid dysfunction of mother, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64821	Anemia of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64822	Anemia of mother, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64831	Drug dependence of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64832	Drug dependence of mother, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64841	Mental disorders of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64842	Mental disorders of mother, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64851	Congenital cardiovascular disorders of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64852	Congenital cardiovascular disorders of mother, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64861	Other cardiovascular diseases of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64862	Other cardiovascular diseases of mother, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64871	Bone and joint disorders of back, pelvis, and lower limbs of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64872	Bone and joint disorders of back, pelvis, and lower limbs of mother, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64881	Abnormal glucose tolerance of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64882	Abnormal glucose tolerance of mother, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64891	Other current conditions classifiable elsewhere of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64892	Other current conditions classifiable elsewhere of mother, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64901	Tobacco use disorder complicating pregnancy, childbirth, or the puerperium, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64902	Tobacco use disorder complicating pregnancy, childbirth, or the puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64911	Obesity complicating pregnancy, childbirth, or the puerperium, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64912	Obesity complicating pregnancy, childbirth, or the puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64921	Bariatric surgery status complicating pregnancy, childbirth, or the puerperium, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64922	Bariatric surgery status complicating pregnancy, childbirth, or the puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64931	Coagulation defects complicating pregnancy, childbirth, or the puerperium, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64932	Coagulation defects complicating pregnancy, childbirth, or the puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64941	Epilepsy complicating pregnancy, childbirth, or the puerperium, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64942	Epilepsy complicating pregnancy, childbirth, or the puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
64951	Spotting complicating pregnancy, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
64971	Cervical shortening, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65101	Twin pregnancy, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65111	Triplet pregnancy, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65121	Quadruplet pregnancy, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65131	Twin pregnancy with fetal loss and retention of one fetus, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65141	Triplet pregnancy with fetal loss and retention of one or more fetus(es), delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65151	Quadruplet pregnancy with fetal loss and retention of one or more fetus(es), delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65161	Other multiple pregnancy with fetal loss and retention of one or more fetus(es), delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65171	Multiple gestation following (elective) fetal reduction,delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65181	Other specified multiple gestation, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65191	Unspecified multiple gestation, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65201	Unstable lie, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65211	Breech or other malpresentation successfully converted to cephalic presentation, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65221	Breech presentation without mention of version, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65231	Transverse or oblique presentation, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65241	Face or brow presentation, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65251	High head at term, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65261	Multiple gestation with malpresentation of one fetus or more, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65271	Prolapsed arm of fetus, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65281	Other specified malposition or malpresentation, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65291	Unspecified malposition or malpresentation, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65301	Major abnormality of bony pelvis, not further specified, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65311	Generally contracted pelvis, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65321	Inlet contraction of pelvis, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65331	Outlet contraction of pelvis, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65341	Fetopelvic disproportion, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65351	Unusually large fetus causing disproportion, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65361	Hydrocephalic fetus causing disproportion, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65371	Other fetal abnormality causing disproportion, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65381	Disproportion of other origin, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65391	Unspecified disproportion, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65401	Congenital abnormalities of uterus, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65402	Congenital abnormalities of uterus, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
65411	Tumors of body of uterus, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65412	Tumors of body of uterus, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
65421	Previous cesarean delivery, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65431	Retroverted and incarcerated gravid uterus, delivered, with mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65432	Retroverted and incarcerated gravid uterus, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
65451	Cervical incompetence, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65452	Cervical incompetence, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
65461	Other congenital or acquired abnormality of cervix, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65462	Other congenital or acquired abnormality of cervix, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
65471	Congenital or acquired abnormality of vagina, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65472	Congenital or acquired abnormality of vagina, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
65481	Congenital or acquired abnormality of vulva, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65482	Congenital or acquired abnormality of vulva, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
65491	Other and unspecified abnormality of organs and soft tissues of pelvis, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65492	Other and unspecified abnormality of organs and soft tissues of pelvis, delivered, with mention of postpartum complication	Unclassified Delivery	ICD -9-CM
65501	Central nervous system malformation in fetus, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65511	Chromosomal abnormality in fetus, affecting management of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65521	Hereditary disease in family possibly affecting fetus, affecting management of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65531	Suspected damage to fetus from viral disease in the mother, affecting management of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65541	Suspected damage to fetus from other disease in the mother, affecting management of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65551	Suspected damage to fetus from drugs, affecting management of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65561	Suspected damage to fetus from radiation, affecting management of mother, delivered,	Unclassified Delivery	ICD-9-CM
65571	Decreased fetal movements, affecting management of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65581	Other known or suspected fetal abnormality, not elsewhere classified, affecting management of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65591	Unspecified suspected fetal abnormality, affecting management of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65601	Fetal-maternal hemorrhage, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65611	Rhesus isoimmunization, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65621	Isoimmunization from other and unspecified blood-group incompatibility, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65631	Fetal distress, affecting management of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65651	Poor fetal growth, affecting management of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65661	Excessive fetal growth, affecting management of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65671	Other placental conditions, affecting management of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65681	Other specified fetal and placental problems, affecting management of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65691	Unspecified fetal and placental problem, affecting management of mother, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65701	Polyhydramnios, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65801	Oligohydramnios, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65811	Premature rupture of membranes, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65821	Delayed delivery after spontaneous or unspecified rupture of membranes, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65831	Delayed delivery after artificial rupture of membranes, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65841	Infection of amniotic cavity, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65881	Other problems associated with amniotic cavity and membranes, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65891	Unspecified problem associated with amniotic cavity and membranes, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65901	Failed mechanical induction of labor, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65911	Failed medical or unspecified induction of labor, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65921	Maternal pyrexia during labor, unspecified, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65931	Generalized infection during labor, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65941	Grand multiparity, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65951	Elderly primigravida, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65961	Elderly multigravida, delivered with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65971	Abnormality in fetal heart rate or rhythm, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65981	Other specified indications for care or intervention related to labor and delivery, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
65991	Unspecified indication for care or intervention related to labor and delivery, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66001	Obstruction caused by malposition of fetus at onset of labor, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66011	Obstruction by bony pelvis during labor, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66021	Obstruction by abnormal pelvic soft tissues during labor, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66031	Deep transverse arrest and persistent occipitoposterior position, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66041	Shoulder (girdle) dystocia, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66051	Locked twins, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66061	Unspecified failed trial of labor, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66071	Failed forceps or vacuum extractor, unspecified, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66081	Other causes of obstructed labor, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66091	Unspecified obstructed labor, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66101	Primary uterine inertia, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66111	Secondary uterine inertia, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66121	Other and unspecified uterine inertia, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66131	Precipitate labor, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66141	Hypertonic, incoordinate, or prolonged uterine contractions, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66191	Unspecified abnormality of labor, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66201	Prolonged first stage of labor, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66211	Unspecified prolonged labor, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66221	Prolonged second stage of labor, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66231	Delayed delivery of second twin, triplet, etc., delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66301	Prolapse of cord complicating labor and delivery, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66311	Cord around neck, with compression, complicating labor and delivery, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66321	Other and unspecified cord entanglement, with compression, complicating labor and delivery, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66331	Other and unspecified cord entanglement, without mention of compression, complicating labor and delivery, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66341	Short cord complicating labor and delivery, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66351	Vasa previa complicating labor and delivery, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66361	Vascular lesions of cord complicating labor and delivery, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66381	Other umbilical cord complications complicating labor and delivery, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66391	Unspecified umbilical cord complication complicating labor and delivery, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66401	First-degree perineal laceration, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66411	Second-degree perineal laceration, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66421	Third-degree perineal laceration, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66431	Fourth-degree perineal laceration, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66441	Unspecified perineal laceration, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66451	Vulvar and perineal hematoma, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66461	Anal sphincter tear complicating delivery, not associated with third-degree perineal laceration, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66481	Other specified trauma to perineum and vulva, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66491	Unspecified trauma to perineum and vulva, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66501	Rupture of uterus before onset of labor, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66511	Rupture of uterus during labor, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66522	Inversion of uterus, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
66531	Laceration of cervix, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66541	High vaginal laceration, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66551	Other injury to pelvic organs, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66561	Damage to pelvic joints and ligaments, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66571	Pelvic hematoma, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66581	Other specified obstetrical trauma, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66591	Unspecified obstetrical trauma, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66602	Third-stage postpartum hemorrhage, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
66612	Other immediate postpartum hemorrhage, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
66622	Delayed and secondary postpartum hemorrhage, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
66632	Postpartum coagulation defects, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
66702	Retained placenta without hemorrhage, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
66712	Retained portions of placenta or membranes, without hemorrhage, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
66801	Pulmonary complications of anesthesia or other sedation in labor and delivery, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
668 02	Pulmonary complications of anesthesia or other sedation in labor and delivery, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
66811	Cardiac complications of anesthesia or other sedation in labor and delivery, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66812	Cardiac complications of anesthesia or other sedation in labor and delivery, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
66821	Central nervous system complications of anesthesia or other sedation in labor and delivery, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66822	Central nervous system complications of anesthesia or other sedation in labor and delivery, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
66881	Other complications of anesthesia or other sedation in labor and delivery, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66882	Other complications of anesthesia or other sedation in labor and delivery, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
66891	Unspecified complication of anesthesia and other sedation in labor and delivery, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66892	Unspecified complication of anesthesia and other sedation in labor and delivery, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
66901	Maternal distress complicating labor and delivery, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66902	Maternal distress complicating labor and delivery, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
66911	Shock during or following labor and delivery, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66912	Shock during or following labor and delivery, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
66921	Maternal hypotension syndrome, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66922	Maternal hypotension syndrome, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
66932	Acute kidney failure following labor and delivery, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
66941	Other complications of obstetrical surgery and procedures, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66942	Other complications of obstetrical surgery and procedures, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
66951	Forceps or vacuum extractor delivery without mention of indication, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66961	Breech extraction, without mention of indication, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66971	Cesarean delivery, without mention of indication, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66981	Other complications of labor and delivery, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66982	Other complications of labor and delivery, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
66991	Unspecified complication of labor and delivery, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
66992	Unspecified complication of labor and delivery, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67002	Major puerperal infection, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67012	Puerperal endometritis, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67022	Puerperal sepsis, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67032	Puerperal septic thrombophlebitis, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67082	Other major puerperal infection, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67101	Varicose veins of legs complicating pregnancy and the puerperium, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67102	Varicose veins of legs complicating pregnancy and the puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67111	Varicose veins of vulva and perineum complicating pregnancy and the puerperium, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67112	Varicose veins of vulva and perineum complicating pregnancy and the puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67121	Superficial thrombophlebitis complicating pregnancy and the puerperium, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67122	Superficial thrombophlebitis complicating pregnancy and the puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67131	Deep phlebothrombosis, antepartum, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67142	Deep phlebothrombosis, postpartum, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67151	Other phlebitis and thrombosis complicating pregnancy and the puerperium, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67152	Other phlebitis and thrombosis complicating pregnancy and the puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67181	Other venous complications of pregnancy and the puerperium, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67182	Other venous complications of pregnancy and the puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67191	Unspecified venous complication of pregnancy and the puerperium, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67192	Unspecified venous complication of pregnancy and the puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67202	Pyrexia of unknown origin during the puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67301	Obstetrical air embolism, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67302	Obstetrical air embolism, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67311	Amniotic fluid embolism, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67312	Amniotic fluid embolism, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67321	Obstetrical blood-clot embolism, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67331	Obstetrical pyemic and septic embolism, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67332	Obstetrical pyemic and septic embolism, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67381	Other obstetrical pulmonary embolism, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67382	Other obstetrical pulmonary embolism, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67401	Cerebrovascular disorders in the puerperium, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67402	Cerebrovascular disorders in the puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67412	Disruption of cesarean wound, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67422	Disruption of perineal wound, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67432	Other complications of obstetrical surgical wounds, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67442	Placental polyp, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67451	Peripartum cardiomyopathy, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67452	Peripartum cardiomyopathy, delivered, with mention of postpartum condition	Unclassified Delivery	ICD-9-CM
67482	Other complications of puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67492	Unspecified complications of puerperium, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67501	Infections of nipple associated with childbirth, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67502	Infections of nipple associated with childbirth, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67511	Abscess of breast associated with childbirth, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67512	Abscess of breast associated with childbirth, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67521	Nonpurulent mastitis associated with childbirth, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67522	Nonpurulent mastitis associated with childbirth, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67581	Other specified infections of the breast and nipple associated with childbirth, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67582	Other specified infections of the breast and nipple associated with childbirth, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67591	Unspecified infection of the breast and nipple associated with childbirth, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67592	Unspecified infection of the breast and nipple associated with childbirth, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67601	Retracted nipple associated with childbirth, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67602	Retracted nipple associated with childbirth, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67611	Cracked nipple associated with childbirth, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67612	Cracked nipple associated with childbirth, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67621	Engorgement of breasts associated with childbirth, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67622	Engorgement of breasts associated with childbirth, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67631	Other and unspecified disorder of breast associated with childbirth, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67632	Other and unspecified disorder of breast associated with childbirth, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67641	Failure of lactation, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67642	Failure of lactation, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67651	Suppressed lactation, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67652	Suppressed lactation, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67661	Galactorrhea associated with childbirth, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67662	Galactorrhea associated with childbirth, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67681	Other disorders of lactation, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67682	Other disorders of lactation, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67691	Unspecified disorder of lactation, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67692	Unspecified disorder of lactation, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67801	Fetal hematologic conditions, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67811	Fetal conjoined twins, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67901	Maternal complications from in utero procedure, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67902	Maternal complications from in utero procedure, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
67911	Fetal complications from in utero procedure, delivered, with or without mention of antepartum condition	Unclassified Delivery	ICD-9-CM
67912	Fetal complications from in utero procedure, delivered, with mention of postpartum complication	Unclassified Delivery	ICD-9-CM
Z388	Other multiple liveborn infant, unspecified as to place of birth	Live Birth	ICD-10-CM
Z387	Other multiple liveborn infant, born outside hospital	Live Birth	ICD-10-CM
Z3869	Other multiple liveborn infant, delivered by cesarean	Live Birth	ICD-10-CM
Z3868	Other multiple liveborn infant, delivered vaginally	Live Birth	ICD-10-CM
Z3866	Quintuplet liveborn infant, delivered by cesarean	Live Birth	ICD-10-CM
Z3865	Quintuplet liveborn infant, delivered vaginally	Live Birth	ICD-10-CM
Z3864	Quadruplet liveborn infant, delivered by cesarean	Live Birth	ICD-10-CM
Z3863	Quadruplet liveborn infant, delivered vaginally	Live Birth	ICD-10-CM
Z3862	Triplet liveborn infant, delivered by cesarean	Live Birth	ICD-10-CM
Z3861	Triplet liveborn infant, delivered vaginally	Live Birth	ICD-10-CM
Z385	Twin liveborn infant, unspecified as to place of birth	Live Birth	ICD-10-CM
Z384	Twin liveborn infant, born outside hospital	Live Birth	ICD-10-CM
Z3831	Twin liveborn infant, delivered by cesarean	Live Birth	ICD-10-CM
Z3830	Twin liveborn infant, delivered vaginally	Live Birth	ICD-10-CM
Z382	Single liveborn infant, unspecified as to place of birth	Live Birth	ICD-10-CM
Z381	Single liveborn infant, born outside hospital	Live Birth	ICD-10-CM
Z3801	Single liveborn infant, delivered by cesarean	Live Birth	ICD-10-CM
Z3800	Single liveborn infant, delivered vaginally	Live Birth	ICD-10-CM
Z379	Outcome of delivery, unspecified	Unclassified delivery	ICD-10-CM
Z3769	Other multiple births, some liveborn	Mixed Delivery	ICD-10-CM
Z3764	Sextuplets, some liveborn	Mixed Delivery	ICD-10-CM
Z3763	Quintuplets, some liveborn	Mixed Delivery	ICD-10-CM
Z3762	Quadruplets, some liveborn	Mixed Delivery	ICD-10-CM
Z3761	Triplets, some liveborn	Mixed Delivery	ICD-10-CM
Z3760	Multiple births, unspecified, some liveborn	Mixed Delivery	ICD-10-CM
Z3759	Other multiple births, all liveborn	Live Birth	ICD-10-CM
Z3754	Sextuplets, all liveborn	Live Birth	ICD-10-CM
Z3753	Quintuplets, all liveborn	Live Birth	ICD-10-CM
Z3752	Quadruplets, all liveborn	Live Birth	ICD-10-CM
Z3751	Triplets, all liveborn	Live Birth	ICD-10-CM
Z3750	Multiple births, unspecified, all liveborn	Live Birth	ICD-10-CM
Z373	Twins, one liveborn and one stillborn	Mixed Delivery	ICD-10-CM
Z372	Twins, both liveborn	Live Birth	ICD-10-CM
Z370	Single live birth	Live Birth	ICD-10-CM
O9A52	Psychological abuse complicating childbirth	Unclassified delivery	ICD-10-CM
O9A42	Sexual abuse complicating childbirth	Unclassified delivery	ICD-10-CM
O9A32	Physical abuse complicating childbirth	Unclassified delivery	ICD-10-CM
O9A22	Injury, poisoning and certain other consequences of external causes complicating childbirth	Unclassified delivery	ICD-10-CM
O9A12	Malignant neoplasm complicating childbirth	Unclassified delivery	ICD-10-CM
O99844	Bariatric surgery status complicating childbirth	Unclassified delivery	ICD-10-CM
O99834	Other infection carrier state complicating childbirth	Unclassified delivery	ICD-10-CM
O99824	Streptococcus B carrier state complicating childbirth	Unclassified delivery	ICD-10-CM
O99814	Abnormal glucose complicating childbirth	Unclassified delivery	ICD-10-CM
O9972	Diseases of the skin and subcutaneous tissue complicating childbirth	Unclassified delivery	ICD-10-CM
O9962	Diseases of the digestive system complicating childbirth	Unclassified delivery	ICD-10-CM
O9952	Diseases of the respiratory system complicating childbirth	Unclassified delivery	ICD-10-CM
O9942	Diseases of the circulatory system complicating childbirth	Unclassified delivery	ICD-10-CM
O99354	Diseases of the nervous system complicating childbirth	Unclassified Delivery	ICD-10-CM
O99344	Other mental disorders complicating childbirth	Unclassified delivery	ICD-10-CM
O99334	Smoking (tobacco) complicating childbirth	Unclassified delivery	ICD-10-CM
O99324	Drug use complicating childbirth	Unclassified delivery	ICD-10-CM
O99314	Alcohol use complicating childbirth	Unclassified delivery	ICD-10-CM
O99284	Endocrine, nutritional and metabolic diseases complicating childbirth	Unclassified delivery	ICD-10-CM
O99214	Obesity complicating childbirth	Unclassified delivery	ICD-10-CM
O9912	Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating childbirth	Unclassified delivery	ICD-10-CM
O9892	Unspecified maternal infectious and parasitic disease complicating childbirth	Unclassified delivery	ICD-10-CM
O9882	Other maternal infectious and parasitic diseases complicating childbirth	Unclassified delivery	ICD-10-CM
O9872	Human immunodeficiency virus [HIV] disease complicating childbirth	Unclassified delivery	ICD-10-CM
O9862	Protozoal diseases complicating childbirth	Unclassified delivery	ICD-10-CM
O9852	Other viral diseases complicating childbirth	Unclassified delivery	ICD-10-CM
O9842	Viral hepatitis complicating childbirth	Unclassified delivery	ICD-10-CM
O9822	Gonorrhea complicating childbirth	Unclassified delivery	ICD-10-CM
O9812	Syphilis complicating childbirth	Unclassified delivery	ICD-10-CM
O9802	Tuberculosis complicating childbirth	Unclassified delivery	ICD-10-CM
O8882	Other embolism in childbirth	Unclassified delivery	ICD-10-CM
O8832	Pyemic and septic embolism in childbirth	Unclassified delivery	ICD-10-CM
O8822	Thromboembolism in childbirth	Unclassified delivery	ICD-10-CM
O8812	Amniotic fluid embolism in childbirth	Unclassified delivery	ICD-10-CM
O8802	Air embolism in childbirth	Unclassified delivery	ICD-10-CM
O82	Encounter for cesarean delivery without indication	Unclassified delivery	ICD-10-CM
O80	Encounter for full-term uncomplicated delivery	Unclassified delivery	ICD-10-CM
O779	Labor and delivery complicated by fetal stress, unspecified	Unclassified delivery	ICD-10-CM
O778	Labor and delivery complicated by other evidence of fetal stress	Unclassified delivery	ICD-10-CM
O771	Fetal stress in labor or delivery due to drug administration	Unclassified delivery	ICD-10-CM
O770	Labor and delivery complicated by meconium in amniotic fluid	Unclassified Delivery	ICD-10-CM
O76	Abnormality in fetal heart rate and rhythm complicating labor and delivery	Unclassified delivery	ICD-10-CM
O759	Complication of labor and delivery, unspecified	Unclassified delivery	ICD-10-CM
O7589	Other specified complications of labor and delivery	Unclassified delivery	ICD-10-CM
O7582	Onset (spontaneous) of labor after 37 completed weeks of gestation but before 39 completed weeks gestation, with delivery by (planned) cesarean section	Live Birth	ICD-10-CM
O7581	Maternal exhaustion complicating labor and delivery	Unclassified delivery	ICD-10-CM
O755	Delayed delivery after artificial rupture of membranes	Unclassified delivery	ICD-10-CM
O751	Shock during or following labor and delivery	Unclassified delivery	ICD-10-CM
O750	Maternal distress during labor and delivery	Unclassified delivery	ICD-10-CM
O749	Complication of anesthesia during labor and delivery, unspecified	Unclassified delivery	ICD-10-CM
O748	Other complications of anesthesia during labor and delivery	Unclassified delivery	ICD-10-CM
O747	Failed or difficult intubation for anesthesia during labor and delivery	Unclassified delivery	ICD-10-CM
O746	Other complications of spinal and epidural anesthesia during labor and delivery	Unclassified delivery	ICD-10-CM
O745	Spinal and epidural anesthesia-induced headache during labor and delivery	Unclassified delivery	ICD-10-CM
O744	Toxic reaction to local anesthesia during labor and delivery	Unclassified delivery	ICD-10-CM
O743	Central nervous system complications of anesthesia during labor and delivery	Unclassified delivery	ICD-10-CM
O742	Cardiac complications of anesthesia during labor and delivery	Unclassified delivery	ICD-10-CM
O741	Other pulmonary complications of anesthesia during labor and delivery	Unclassified delivery	ICD-10-CM
O740	Aspiration pneumonitis due to anesthesia during labor and delivery	Unclassified delivery	ICD-10-CM
O709	Perineal laceration during delivery, unspecified	Unclassified delivery	ICD-10-CM
O704	Anal sphincter tear complicating delivery, not associated with third degree laceration	Unclassified delivery	ICD-10-CM
O703	Fourth degree perineal laceration during delivery	Unclassified delivery	ICD-10-CM
O7023	Third degree perineal laceration during delivery, IIIc	Unclassified delivery	ICD-10-CM
O7022	Third degree perineal laceration during delivery, IIIb	Unclassified delivery	ICD-10-CM
O7021	Third degree perineal laceration during delivery, IIIa	Unclassified delivery	ICD-10-CM
O7020	Third degree perineal laceration during delivery, unspecified	Unclassified delivery	ICD-10-CM
O701	Second degree perineal laceration during delivery	Unclassified delivery	ICD-10-CM
O700	First degree perineal laceration during delivery	Unclassified delivery	ICD-10-CM
O699XX9	Labor and delivery complicated by cord complication, unspecified, other fetus	Unclassified delivery	ICD-10-CM
O699XX5	Labor and delivery complicated by cord complication, unspecified, fetus 5	Unclassified delivery	ICD-10-CM
O699XX4	Labor and delivery complicated by cord complication, unspecified, fetus 4	Unclassified delivery	ICD-10-CM
O699XX3	Labor and delivery complicated by cord complication, unspecified, fetus 3	Unclassified delivery	ICD-10-CM
O699XX2	Labor and delivery complicated by cord complication, unspecified, fetus 2	Unclassified delivery	ICD-10-CM
O699XX1	Labor and delivery complicated by cord complication, unspecified, fetus 1	Unclassified delivery	ICD-10-CM
O699XX0	Labor and delivery complicated by cord complication, unspecified, not applicable or unspecified	Unclassified delivery	ICD-10-CM
O6989X9	Labor and delivery complicated by other cord complications, other fetus	Unclassified delivery	ICD-10-CM
O6989X5	Labor and delivery complicated by other cord complications, fetus 5	Unclassified delivery	ICD-10-CM
O6989X4	Labor and delivery complicated by other cord complications, fetus 4	Unclassified delivery	ICD-10-CM
O6989X3	Labor and delivery complicated by other cord complications, fetus 3	Unclassified delivery	ICD-10-CM
O6989X2	Labor and delivery complicated by other cord complications, fetus 2	Unclassified delivery	ICD-10-CM
O6989X1	Labor and delivery complicated by other cord complications, fetus 1	Unclassified delivery	ICD-10-CM
O6989X0	Labor and delivery complicated by other cord complications, not applicable or unspecified	Unclassified delivery	ICD-10-CM
O6982X9	Labor and delivery complicated by other cord entanglement, without compression, other fetus	Unclassified delivery	ICD-10-CM
O6982X5	Labor and delivery complicated by other cord entanglement, without compression, fetus 5	Unclassified delivery	ICD-10-CM
O6982X4	Labor and delivery complicated by other cord entanglement, without compression, fetus 4	Unclassified delivery	ICD-10-CM
O6982X3	Labor and delivery complicated by other cord entanglement, without compression, fetus 3	Unclassified delivery	ICD-10-CM
O6982X2	Labor and delivery complicated by other cord entanglement, without compression, fetus 2	Unclassified delivery	ICD-10-CM
O6982X1	Labor and delivery complicated by other cord entanglement, without compression, fetus 1	Unclassified delivery	ICD-10-CM
O6982X0	Labor and delivery complicated by other cord entanglement, without compression, not applicable or unspecified	Unclassified delivery	ICD-10-CM
O6981X9	Labor and delivery complicated by cord around neck, without compression, other fetus	Unclassified delivery	ICD-10-CM
O6981X5	Labor and delivery complicated by cord around neck, without compression, fetus 5	Unclassified delivery	ICD-10-CM
O6981X4	Labor and delivery complicated by cord around neck, without compression, fetus 4	Unclassified delivery	ICD-10-CM
O6981X3	Labor and delivery complicated by cord around neck, without compression, fetus 3	Unclassified delivery	ICD-10-CM
O6981X2	Labor and delivery complicated by cord around neck, without compression, fetus 2	Unclassified delivery	ICD-10-CM
O6981X1	Labor and delivery complicated by cord around neck, without compression, fetus 1	Unclassified delivery	ICD-10-CM
O6981X0	Labor and delivery complicated by cord around neck, without compression, not applicable or unspecified	Unclassified delivery	ICD-10-CM
O695XX9	Labor and delivery complicated by vascular lesion of cord, other fetus	Unclassified delivery	ICD-10-CM
O695XX5	Labor and delivery complicated by vascular lesion of cord, fetus 5	Unclassified delivery	ICD-10-CM
O695XX4	Labor and delivery complicated by vascular lesion of cord, fetus 4	Unclassified delivery	ICD-10-CM
O695XX3	Labor and delivery complicated by vascular lesion of cord, fetus 3	Unclassified delivery	ICD-10-CM
O695XX2	Labor and delivery complicated by vascular lesion of cord, fetus 2	Unclassified delivery	ICD-10-CM
O695XX1	Labor and delivery complicated by vascular lesion of cord, fetus 1	Unclassified delivery	ICD-10-CM
O695XX0	Labor and delivery complicated by vascular lesion of cord, not applicable or unspecified	Unclassified delivery	ICD-10-CM
O694XX9	Labor and delivery complicated by vasa previa, other fetus	Unclassified delivery	ICD-10-CM
O694XX5	Labor and delivery complicated by vasa previa, fetus 5	Unclassified delivery	ICD-10-CM
O694XX4	Labor and delivery complicated by vasa previa, fetus 4	Unclassified delivery	ICD-10-CM
O694XX3	Labor and delivery complicated by vasa previa, fetus 3	Unclassified delivery	ICD-10-CM
O694XX2	Labor and delivery complicated by vasa previa, fetus 2	Unclassified delivery	ICD-10-CM
O694XX1	Labor and delivery complicated by vasa previa, fetus 1	Unclassified delivery	ICD-10-CM
O694XX0	Labor and delivery complicated by vasa previa, not applicable or unspecified	Unclassified delivery	ICD-10-CM
O693XX9	Labor and delivery complicated by short cord, other fetus	Unclassified delivery	ICD-10-CM
O693XX5	Labor and delivery complicated by short cord, fetus 5	Unclassified delivery	ICD-10-CM
O693XX4	Labor and delivery complicated by short cord, fetus 4	Unclassified delivery	ICD-10-CM
O693XX3	Labor and delivery complicated by short cord, fetus 3	Unclassified delivery	ICD-10-CM
O693XX2	Labor and delivery complicated by short cord, fetus 2	Unclassified delivery	ICD-10-CM
O693XX1	Labor and delivery complicated by short cord, fetus 1	Unclassified delivery	ICD-10-CM
O693XX0	Labor and delivery complicated by short cord, not applicable or unspecified	Unclassified delivery	ICD-10-CM
O6982X9	Labor and delivery complicated by other cord entanglement, with compression, other fetus	Unclassified delivery	ICD-10-CM
O692XX5	Labor and delivery complicated by other cord entanglement, with compression, fetus 5	Unclassified delivery	ICD-10-CM
O692XX4	Labor and delivery complicated by other cord entanglement, with compression, fetus 4	Unclassified delivery	ICD-10-CM
O692XX3	Labor and delivery complicated by other cord entanglement, with compression, fetus 3	Unclassified delivery	ICD-10-CM
O692XX2	Labor and delivery complicated by other cord entanglement, with compression, fetus 2	Unclassified delivery	ICD-10-CM
O692XX1	Labor and delivery complicated by other cord entanglement, with compression, fetus 1	Unclassified delivery	ICD-10-CM
O692XX0	Labor and delivery complicated by other cord entanglement, with compression, not applicable or unspecified	Unclassified delivery	ICD-10-CM
O691XX9	Labor and delivery complicated by cord around neck, with compression, other fetus	Unclassified delivery	ICD-10-CM
O691XX5	Labor and delivery complicated by cord around neck, with compression, fetus 5	Unclassified delivery	ICD-10-CM
O691XX4	Labor and delivery complicated by cord around neck, with compression, fetus 4	Unclassified delivery	ICD-10-CM
O691XX3	Labor and delivery complicated by cord around neck, with compression, fetus 3	Unclassified delivery	ICD-10-CM
O691XX2	Labor and delivery complicated by cord around neck, with compression, fetus 2	Unclassified delivery	ICD-10-CM
O691XX1	Labor and delivery complicated by cord around neck, with compression, fetus 1	Unclassified delivery	ICD-10-CM
O691XX0	Labor and delivery complicated by cord around neck, with compression, not applicable or unspecified	Unclassified delivery	ICD-10-CM
O690XX9	Labor and delivery complicated by prolapse of cord, other fetus	Unclassified delivery	ICD-10-CM
O690XX5	Labor and delivery complicated by prolapse of cord, fetus 5	Unclassified delivery	ICD-10-CM
O690XX4	Labor and delivery complicated by prolapse of cord, fetus 4	Unclassified delivery	ICD-10-CM
O690XX3	Labor and delivery complicated by prolapse of cord, fetus 3	Unclassified delivery	ICD-10-CM
O690XX2	Labor and delivery complicated by prolapse of cord, fetus 2	Unclassified delivery	ICD-10-CM
O690XX1	Labor and delivery complicated by prolapse of cord, fetus 1	Unclassified delivery	ICD-10-CM
O690XX0	Labor and delivery complicated by prolapse of cord, not applicable or unspecified	Unclassified delivery	ICD-10-CM
O68	Labor and delivery complicated by abnormality of fetal acid-base balance	Unclassified delivery	ICD-10-CM
O679	Intrapartum hemorrhage, unspecified	Unclassified delivery	ICD-10-CM
O678	Other intrapartum hemorrhage	Unclassified delivery	ICD-10-CM
O670	Intrapartum hemorrhage with coagulation defect	Unclassified delivery	ICD-10-CM
O665	Attempted application of vacuum or forceps, with subsequent delivery by forceps or cesarean delivery	Unclassified delivery	ICD-10-CM
O632	Delayed delivery of second twin, triplet, etc	Unclassified delivery	ICD-10-CM
O6023X9	Term delivery with preterm labor, third trimester, other fetus	Live Birth	ICD-10-CM
O6023X5	Term delivery with preterm labor, third trimester, fetus 5	Live Birth	ICD-10-CM
O6023X4	Term delivery with preterm labor, third trimester, fetus 4	Live Birth	ICD-10-CM
O6023X3	Term delivery with preterm labor, third trimester, fetus 3	Live Birth	ICD-10-CM
O6023X2	Term delivery with preterm labor, third trimester, fetus 2	Live Birth	ICD-10-CM
O6023X1	Term delivery with preterm labor, third trimester, fetus 1	Live Birth	ICD-10-CM
O6023X0	Term delivery with preterm labor, third trimester, not applicable or unspecified	Live Birth	ICD-10-CM
O6022X9	Term delivery with preterm labor, second trimester, other fetus	Live Birth	ICD-10-CM
O6022X5	Term delivery with preterm labor, second trimester, fetus 5	Live Birth	ICD-10-CM
O6022X4	Term delivery with preterm labor, second trimester, fetus 4	Live Birth	ICD-10-CM
O6022X3	Term delivery with preterm labor, second trimester, fetus 3	Live Birth	ICD-10-CM
O6022X2	Term delivery with preterm labor, second trimester, fetus 2	Live Birth	ICD-10-CM
O6022X1	Term delivery with preterm labor, second trimester, fetus 1	Live Birth	ICD-10-CM
O6022X0	Term delivery with preterm labor, second trimester, not applicable or unspecified	Live Birth	ICD-10-CM
O4292	Full-term premature rupture of membranes, unspecified as to length of time between rupture and onset of labor	Unclassified delivery	ICD-10-CM
O4212	Full-term premature rupture of membranes, onset of labor more than 24 hours following rupture	Unclassified delivery	ICD-10-CM
O4202	Full-term premature rupture of membranes, onset of labor within 24 hours of rupture	Unclassified delivery	ICD-10-CM
O2672	Subluxation of symphysis (pubis) in childbirth	Unclassified delivery	ICD-10-CM
O2662	Liver and biliary tract disorders in childbirth	Unclassified delivery	ICD-10-CM
O252	Malnutrition in childbirth	Unclassified delivery	ICD-10-CM
O2492	Unspecified diabetes mellitus in childbirth	Unclassified delivery	ICD-10-CM
O2482	Other pre-existing diabetes mellitus in childbirth	Unclassified delivery	ICD-10-CM
O24429	Gestational diabetes mellitus in childbirth, unspecified control	Unclassified delivery	ICD-10-CM
O24425	Gestational diabetes mellitus in childbirth, controlled by oral hypoglycemic drugs	Unclassified delivery	ICD-10-CM
O24424	Gestational diabetes mellitus in childbirth, insulin controlled	Unclassified delivery	ICD-10-CM
O24420	Gestational diabetes mellitus in childbirth, diet controlled	Unclassified delivery	ICD-10-CM
O2432	Unspecified pre-existing diabetes mellitus in childbirth	Unclassified delivery	ICD-10-CM
O2412	Pre-existing type 2 diabetes mellitus, in childbirth	Unclassified delivery	ICD-10-CM
O2402	Pre-existing type 1 diabetes mellitus, in childbirth	Unclassified delivery	ICD-10-CM
O164	Unspecified maternal hypertension, complicating childbirth	Unclassified delivery	ICD-10-CM
O1494	Unspecified pre-eclampsia, complicating childbirth	Unclassified delivery	ICD-10-CM
O1424	HELLP syndrome, complicating childbirth	Unclassified delivery	ICD-10-CM
O1414	Severe pre-eclampsia complicating childbirth	Unclassified delivery	ICD-10-CM
O1404	Mild to moderate pre-eclampsia, complicating childbirth	Unclassified delivery	ICD-10-CM
O134	Gestational [pregnancy-induced] hypertension without significant proteinuria, complicating childbirth	Unclassified delivery	ICD-10-CM
O1224	Gestational edema with proteinuria, complicating childbirth	Unclassified delivery	ICD-10-CM
O1214	Gestational proteinuria, complicating childbirth	Unclassified delivery	ICD-10-CM
O1204	Gestational edema, complicating childbirth	Unclassified delivery	ICD-10-CM
O114	Pre-existing hypertension with pre-eclampsia, complicating childbirth	Unclassified delivery	ICD-10-CM
O1092	Unspecified pre-existing hypertension complicating childbirth	Unclassified delivery	ICD-10-CM
O1042	Pre-existing secondary hypertension complicating childbirth	Unclassified delivery	ICD-10-CM
O1032	Pre-existing hypertensive heart and chronic kidney disease complicating childbirth	Unclassified delivery	ICD-10-CM
O1022	Pre-existing hypertensive chronic kidney disease complicating childbirth	Unclassified delivery	ICD-10-CM
O1012	Pre-existing hypertensive heart disease complicating childbirth	Unclassified delivery	ICD-10-CM
O1002	Pre-existing essential hypertension complicating childbirth	Unclassified delivery	ICD-10-CM
V271x	Mother with single stillborn	Stillbirth	ICD-9-CM
V274x	Mother with twins both stillborn	Stillbirth	ICD-9-CM
V277x	Mother with other multiple birth all stillborn	Stillbirth	ICD-9-CM
65640	Intrauterine death affecting management of mother unspecified as to episode of care	Stillbirth	ICD-9-CM
65641	Intrauterine death affecting management of mother delivered	Stillbirth	ICD-9-CM
65643	Intrauterine death affecting management of mother antepartum	Stillbirth	ICD-9-CM
O364XX0	Maternal care for intrauterine death, not applicable or unspecified	Stillbirth	ICD-10-CM
O364XX1	Maternal care for intrauterine death, fetus 1	Stillbirth	ICD-10-CM
O364XX2	Maternal care for intrauterine death, fetus 2	Stillbirth	ICD-10-CM
O364XX3	Maternal care for intrauterine death, fetus 3	Stillbirth	ICD-10-CM
O364XX4	Maternal care for intrauterine death, fetus 4	Stillbirth	ICD-10-CM
O364XX5	Maternal care for intrauterine death, fetus 5	Stillbirth	ICD-10-CM
O364XX9	Maternal care for intrauterine death, other fetus	Stillbirth	ICD-10-CM
Z371	Single stillbirth	Stillbirth	ICD-10-CM
Z374	Twins, both stillborn	Stillbirth	ICD-10-CM
Z377	Other multiple births, all stillborn	Stillbirth	ICD-10-CM
635xx	Legally induced abortion	Induced Abortion	ICD-9-CM
636xx	Illegal abortion	Induced Abortion	ICD-9-CM
7796	Termination of pregnancy (fetus)	Induced Abortion	ICD-9-CM
O046	Delayed or excessive hemorrhage following (induced) termination of pregnancy	Induced Abortion	ICD-10-CM
O0484	Damage to pelvic organs following (induced) termination of pregnancy	Induced Abortion	ICD-10-CM
O0482	Renal failure following (induced) termination of pregnancy	Induced Abortion	ICD-10-CM
O0483	Metabolic disorder following (induced) termination of pregnancy	Induced Abortion	ICD-10-CM
O0481	Shock following (induced) termination of pregnancy	Induced Abortion	ICD-10-CM
O047	Embolism following (induced) termination of pregnancy	Induced Abortion	ICD-10-CM
O0485	Other venous complications following (induced) termination of pregnancy	Induced Abortion	ICD-10-CM
O0486	Cardiac arrest following (induced) termination of pregnancy	Induced Abortion	ICD-10-CM
O0488	Urinary tract infection following (induced) termination of pregnancy	Induced Abortion	ICD-10-CM
O0489	(Induced) termination of pregnancy with other complications	Induced Abortion	ICD-10-CM
O0480	(Induced) termination of pregnancy with unspecified complications	Induced Abortion	ICD-10-CM
Z332	Encounter for elective termination of pregnancy	Induced Abortion	ICD-10-CM
Z332	Encounter for elective termination of pregnancy	Induced Abortion	ICD-10-CM
O045	Genital tract and pelvic infection following (induced) termination of pregnancy	Induced Abortion	ICD-10-CM
632xx	Missed abortion	Spontaneous Abortion	ICD-9-CM
634xx	Spontaneous abortion	Spontaneous Abortion	ICD-9-CM
6310x	Inappropriate change in quantitative human chorionic gonadotropin (hCG) in early pregnancy	Spontaneous Abortion	ICD-9-CM
6318x	Other abnormal products of conception	Spontaneous Abortion	ICD-9-CM
6370x	Unspecified abortion complicated by genital tract and pelvic infection	Spontaneous Abortion	ICD-9-CM
6371x	Unspecified abortion complicated by delayed or excessive hemorrhage	Spontaneous Abortion	ICD-9-CM
O021	Missed abortion	Spontaneous Abortion	ICD-10-CM
O0281	Inappropriate change in quantitative human chorionic gonadotropin (hCG) in early pregnancy	Spontaneous Abortion	ICD-10-CM
O020	Blighted ovum and nonhydatidiform mole	Spontaneous Abortion	ICD-10-CM
O0289	Other abnormal products of conception	Spontaneous Abortion	ICD-10-CM
O029	Abnormal product of conception, unspecified	Spontaneous Abortion	ICD-10-CM
O036	Delayed or excessive hemorrhage following complete or unspecified spontaneous abortion	Spontaneous Abortion	ICD-10-CM
O031	Delayed or excessive hemorrhage following incomplete spontaneous abortion	Spontaneous Abortion	ICD-10-CM
O0384	Damage to pelvic organs following complete or unspecified spontaneous abortion	Spontaneous Abortion	ICD-10-CM
O0334	Damage to pelvic organs following incomplete spontaneous abortion	Spontaneous Abortion	ICD-10-CM
O0382	Renal failure following complete or unspecified spontaneous abortion	Spontaneous Abortion	ICD-10-CM
O0332	Renal failure following incomplete spontaneous abortion	Spontaneous Abortion	ICD-10-CM
O0383	Metabolic disorder following complete or unspecified spontaneous abortion	Spontaneous Abortion	ICD-10-CM
O0333	Metabolic disorder following incomplete spontaneous abortion	Spontaneous Abortion	ICD-10-CM
O0381	Shock following complete or unspecified spontaneous abortion	Spontaneous Abortion	ICD-10-CM
O0331	Shock following incomplete spontaneous abortion	Spontaneous Abortion	ICD-10-CM
O037	Embolism following complete or unspecified spontaneous abortion	Spontaneous Abortion	ICD-10-CM
O032	Embolism following incomplete spontaneous abortion	Spontaneous Abortion	ICD-10-CM
O0385	Other venous complications following complete or unspecified spontaneous abortion	Spontaneous Abortion	ICD-10-CM
O0386	Cardiac arrest following complete or unspecified spontaneous abortion	Spontaneous Abortion	ICD-10-CM
O0388	Urinary tract infection following complete or unspecified spontaneous abortion	Spontaneous Abortion	ICD-10-CM
O0389	Complete or unspecified spontaneous abortion with other complications	Spontaneous Abortion	ICD-10-CM
O0335	Other venous complications following incomplete spontaneous abortion	Spontaneous Abortion	ICD-10-CM
O0336	Cardiac arrest following incomplete spontaneous abortion	Spontaneous Abortion	ICD-10-CM
O0338	Urinary tract infection following incomplete spontaneous abortion	Spontaneous Abortion	ICD-10-CM
O0339	Incomplete spontaneous abortion with other complications	Spontaneous Abortion	ICD-10-CM
O0380	Unspecified complication following complete or unspecified spontaneous abortion	Spontaneous Abortion	ICD-10-CM
O0330	Unspecified complication following incomplete spontaneous abortion	Spontaneous Abortion	ICD-10-CM
O039	Complete or unspecified spontaneous abortion without complication	Spontaneous Abortion	ICD-10-CM
O034	Incomplete spontaneous abortion without complication	Spontaneous Abortion	ICD-10-CM
633xx	Ectopic pregnancy	Ectopic Pregnancy	ICD-9-CM
O00x	Ectopic pregnancy	Ectopic pregnancy	ICD-10-CM

Table A.2:

Codes for Gestational Age (GA)

Code	GA in weeks	Code Description	Code Type
765.21	23	Less than 24 completed weeks of gestation	ICD-9-CM
765.22	24	24 completed weeks of gestation	ICD-9-CM
765.23	26	25 to 26 completed weeks of gestation	ICD-9-CM
765.24	28	27 to 28 completed weeks of gestation	ICD-9-CM
765.09	28	Extreme immaturity, 2,500 grams and over	ICD-9-CM
765.08	28	Extreme immaturity, 2,000-2,499 grams	ICD-9-CM
765.07	28	Extreme immaturity, 1,750-1,999 grams	ICD-9-CM
765.06	28	Extreme immaturity, 1,500-1,749 grams	ICD-9-CM
765.05	28	Extreme immaturity, 1,250-1,499 grams	ICD-9-CM
765.04	28	Extreme immaturity, 1,000-1,249 grams	ICD-9-CM
765.03	28	Extreme immaturity, 750-999 grams	ICD-9-CM
765.02	28	Extreme immaturity, 500-749 grams	ICD-9-CM
765.01	28	Extreme immaturity, less than 500 grams	ICD-9-CM
765	28	Extreme immaturity, unspecified [weight]	ICD-9-CM
765	28	Disorders relating to extreme immaturity of infant	ICD-9-CM
765.25	30	29 to 30 completed weeks of gestation	ICD-9-CM
765.26	32	31 to 32 completed weeks of gestation	ICD-9-CM
765.27	34	33 to 34 completed weeks of gestation	ICD-9-CM
765.2	35	Preterm, unspecified weeks of gestation	ICD-9-CM
765.19	35	Other preterm infants, 2,500 grams and over	ICD-9-CM
765.18	35	Other preterm infants, 2,000-2,499 grams	ICD-9-CM
765.17	35	Other preterm infants, 1,750-1,999 grams	ICD-9-CM
765.16	35	Other preterm infants, 1,500-1,749 grams	ICD-9-CM
765.15	35	Other preterm infants, 1,250-1,499 grams	ICD-9-CM
765.14	35	Other preterm infants, 1,000-1,249 grams	ICD-9-CM
765.13	35	Other preterm infants, 750-999 grams	ICD-9-CM
765.12	35	Other preterm infants, 500-749 grams	ICD-9-CM
765.11	35	Other preterm infants, less than 500 grams	ICD-9-CM
765.1	35	Other preterm infants, unspecified [weight]	ICD-9-CM
765.1	35	Disorders relating to other preterm infants	ICD-9-CM
765	35	Disorders relating to short gestation and low birthweight	ICD-9-CM
644.21	35	Early onset of delivery, delivered, with or without mention of antepartum condition	ICD-9-CM
765.28	36	35 to 36 completed weeks of gestation	ICD-9-CM
766	40	Disorders relating to long gestation and high birthweight	ICD-9-CM
765.29	39	37 or more completed weeks of gestation	ICD-9-CM
765.2	39	Weeks of gestation	ICD-9-CM
766.2	40	Late infant, not ‘heavy-for-dates’	ICD-9-CM
645.13	40	Post term pregnancy, antepartum condition or complication	ICD-9-CM
645.11	40	Post term pregnancy, delivered, with or without mention of antepartum	ICD-9-CM
645.1	40	post term pregnancy, unspecified as to episode of care or not applicable	ICD-9-CM
645.1	40	Post-term pregnancy	ICD-9-CM
645	40	Late pregnancy	ICD-9-CM
766.21	41	Hypermaturity, Post-term infant (gestation period over 40 completed weeks to 42 completed weeks)	ICD-9-CM
645.23	41	Prolonged pregnancy, antepartum condition or complication	ICD-9-CM
645.21	41	Prolonged pregnancy, delivered, with or without mention of antepartum	ICD-9-CM
645.2	41	Prolonged pregnancy, unspecified as to episode of care or not applicable	ICD-9-CM
645.2	41	Prolonged pregnancy	ICD-9-CM
766.22	42	Prolonged gestation of infant (period over 42 completed weeks)	ICD-9-CM
P07.21	23	Extreme immaturity of newborn, gestational age less than 23 completed weeks	ICD-10-CM
O60.12X0	24	Preterm labor second trimester with preterm delivery second trimester	ICD-10-CM
O60.12X1	24	Preterm labor second trimester with preterm delivery second trimester	ICD-10-CM
O60.12X2	24	Preterm labor second trimester with preterm delivery second trimester	ICD-10-CM
O60.12X3	24	Preterm labor second trimester with preterm delivery second trimester	ICD-10-CM
O60.12X4	24	Preterm labor second trimester with preterm delivery second trimester	ICD-10-CM
O60.12X5	24	Preterm labor second trimester with preterm delivery second trimester	ICD-10-CM
O60.12X9	24	Preterm labor second trimester with preterm delivery second trimester	ICD-10-CM
P07.01	31	Other low birth weight newborn, unspecified weight	ICD-10-CM
P07.00	32	Extremely low birth weight newborn, unspecified weight	ICD-10-CM
P07.02	32	Extremely low birth weight newborn, 500-749 grams	ICD-10-CM
P07.03	32	Extremely low birth weight newborn, 750-999 grams	ICD-10-CM
P07.14	32	Other low birth weight newborn, 1000-1249 grams	ICD-10-CM
P07.15	32	Other low birth weight newborn, 1250-1499 grams	ICD-10-CM
P07.16	32	Other low birth weight newborn, 1500-1749 grams	ICD-10-CM
P07.17	32	Other low birth weight newborn, 1750-1999 grams	ICD-10-CM
P07.18	32	Other low birth weight newborn, 2000-2499 grams	ICD-10-CM
P07.30	33	Preterm newborn, unspecified weeks of gestation	ICD-10-CM
O60.13X0	35	Preterm labor second trimester with preterm delivery third trimester	ICD-10-CM
O60.13X1	35	Preterm labor second trimester with preterm delivery third trimester	ICD-10-CM
O60.13X2	35	Preterm labor second trimester with preterm delivery third trimester	ICD-10-CM
O60.13X3	35	Preterm labor second trimester with preterm delivery third trimester	ICD-10-CM
O60.13X4	35	Preterm labor second trimester with preterm delivery third trimester	ICD-10-CM
O60.13X5	35	Preterm labor second trimester with preterm delivery third trimester	ICD-10-CM
O60.13X9	35	Preterm labor second trimester with preterm delivery third trimester	ICD-10-trimester
P07.10	35	Other low birth weight newborn, unspecified weight	ICD-10-CM
P07.20	35	Extreme immaturity of newborn, unspecified weeks of gestation	ICD-10-CM
O48.0	40	Post-term pregnancy	ICD-10-CM
O48.1	41	Prolonged pregnancy	ICD-10-CM
P08.21	41	Post-term newborn	ICD-10-CM
P08.22	42	Prolonged gestation of newborn	ICD-10-CM
Z3A.49	43	Greater than 42 weeks gestation of pregnancy	ICD-10-CM
O60.14X9	35	Preterm labor third trimester with preterm delivery third trimester	ICD-10-CM
O60.14X5	35	Preterm labor third trimester with preterm delivery third trimester	ICD-10-CM
O60.14X4	35	Preterm labor third trimester with preterm delivery third trimester	ICD-10-CM
O60.14X3	35	Preterm labor third trimester with preterm delivery third trimester	ICD-10-CM
O60.14X2	35	Preterm labor third trimester with preterm delivery third trimester	ICD-10-CM
O60.14X1	35	Preterm labor third trimester with preterm delivery third trimester	ICD-10-CM
O60.14X0	35	Preterm labor third trimester with preterm delivery third trimester	ICD-10-CM
P07.22	23	Extreme immaturity of newborn, gestational age 23 completed weeks	ICD-10-CM
P07.23	24	Extreme immaturity of newborn, gestational age 24 completed weeks	ICD-10-CM
P07.24	25	Extreme immaturity of newborn, gestational age 25 completed weeks	ICD-10-CM
P07.25	26	Extreme immaturity of newborn, gestational age 26 completed weeks	ICD-10-CM
P07.26	27	Extreme immaturity of newborn, gestational age 27 completed weeks	ICD-10-CM
P07.31	28	Preterm newborn, gestational age 28 completed weeks	ICD-10-CM
Z3A.20	20	20 weeks gestation of pregnancy	ICD-10-CM
Z3A.21	21	21 weeks gestation of pregnancy	ICD-10-CM
Z3A.22	22	22 weeks gestation of pregnancy	ICD-10-CM
Z3A.23	23	23 weeks gestation of pregnancy	ICD-10-CM
Z3A.24	24	24 weeks gestation of pregnancy	ICD-10-CM
Z3A.25	25	25 weeks gestation of pregnancy	ICD-10-CM
Z3A.26	26	26 weeks gestation of pregnancy	ICD-10-CM
Z3A.27	27	27 weeks gestation of pregnancy	ICD-10-CM
Z3A.28	28	28 weeks gestation of pregnancy	ICD-10-CM
Z3A.29	29	29 weeks gestation of pregnancy	ICD-10-CM
P07.32	29	Preterm newborn, gestational age 29 completed weeks	ICD-10-CM
Z3A.30	30	30 weeks gestation of pregnancy	ICD-10-CM
P07.33	30	Preterm newborn, gestational age 30 completed weeks	ICD-10-CM
Z3A.31	31	31 weeks gestation of pregnancy	ICD-10-CM
P07.34	31	Preterm newborn, gestational age 31 completed weeks	ICD-10-CM
Z3A.32	32	32 weeks gestation of pregnancy	ICD-10-CM
P07.35	32	Preterm newborn, gestational age 32 completed weeks	ICD-10-CM
Z3A.33	33	33 weeks gestation of pregnancy	ICD-10-CM
P07.36	33	Preterm newborn, gestational age 33 completed weeks	ICD-10-CM
Z3A.34	34	34 weeks gestation of pregnancy	ICD-10-CM
P07.37	34	Preterm newborn, gestational age 34 completed weeks	ICD-10-CM
Z3A.35	35	35 weeks gestation of pregnancy	ICD-10-CM
P07.38	35	Preterm newborn, gestational age 35 completed weeks	ICD-10-CM
Z3A.36	36	36 weeks gestation of pregnancy	ICD-10-CM
P07.39	36	Preterm newborn, gestational age 36 completed weeks	ICD-10-CM
Z3A.37	37	37 weeks gestation of pregnancy	ICD-10-CM
Z3A.38	38	38 weeks gestation of pregnancy	ICD-10-CM
Z3A.39	39	39 weeks gestation of pregnancy	ICD-10-CM
Z3A.40	40	40 weeks gestation of pregnancy	ICD-10-CM
Z3A.41	41	41 weeks gestation of pregnancy	ICD-10-CM
Z3A.42	42	42 weeks gestation of pregnancy	ICD-10-CM

Table A.3:

ICD-9 Codes for Covariates

Condition Category	Subcategory	ICD-9-CMCode	Code Description
Maternal medical complication	Hypertension	401.XX	Essential hypertension
Maternal medical complication	Hypertension	402.XX	Hypertensive heart disease
Maternal medical complication	Hypertension	403.XX	Hypertensive kidney disease
Maternal medical complication	Hypertension	404.XX	Hypertensive heart and kidney disease
Maternal medical complication	Hypertension	405.XX	Secondary hypertension
Maternal medical complication	Preeclampsia or Eclampsia	642.XX	Hypertension complicating pregnancy childbirth and the puerperium
Maternal medical complication	Gestational diabetes	648.00	Diabetes mellitus complicating pregnancy childbirth or the puerperium
Maternal medical complication	Gestational diabetes	648.01	Diabetes mellitus of mother with delivery
Maternal medical complication	Gestational diabetes	648.02	Diabetes mellitus of mother with delivery with postpartum complication
Maternal medical complication	Gestational diabetes	648.03	Antepartum diabetes mellitus
Maternal medical complication	Gestational diabetes	648.04	Postpartum diabetes mellitus
Maternal medical complication	Gestational diabetes	648.8	Abnormal glucose tolerance of mother complicating pregnancy childbirth or the puerperium
Maternal medical complication	Gestational diabetes	648.80	Abnormal glucose tolerance of mother complicating pregnancy childbirth or the puerperium unspecified as to episode of care
Maternal medical complication	Gestational diabetes	648.81	Abnormal glucose tolerance of mother with delivery
Maternal medical complication	Gestational diabetes	648.82	Abnormal glucose tolerance of mother with delivery with postpartum complication
Maternal medical complication	Gestational diabetes	648.83	Abnormal glucose tolerance of mother antepartum
Maternal medical complication	Gestational diabetes	648.84	Abnormal glucose tolerance of mother postpartum
Maternal medical complication	Pre-existing diabetes	250.XX	Diabetes mellitus
Maternal medical complication	Obesity	649.1X	Obesity complicating pregnancy, childbirth, or the puerperium
Maternal medical complication	Obesity	649.2X	Bariatric surgery status complicating pregnancy, childbirth, or the puerperium
Maternal medical complication	Obesity	278.XX	Overweight, obesity and other hyperalimentation
Maternal medical complication	Obesity	V85.3X	Adult body mass index ≥30.0 and ≤40.9
Maternal medical complication	Obesity	V85.4X	Adult body mass index ≥40.0
Maternal medical complication	Anemia	280.X	Iron deficiency anemia
Maternal medical complication	Anemia	281.X	Nutritional deficiency anemia
Maternal medical complication	Anemia	285.2	Anemia in chronic disease and neoplastic disease
Maternal medical complication	Anemia	285.9	Anemia unspecified
Maternal medical complication	Anemia	648.2X	Anemia of mother
Maternal medical complication	Cholestasis	646.7X	Liver and biliary tract disorders in pregnancy, antepartum condition or complication
Maternal medical complication	Periodontal disease	523.XX	Gingival and periodontal diseases
Maternal medical complication	IVF	V2385	Pregnancy resulting from assisted reproductive technology
Infection	Bateriuria	646.5X	Asymptomatic bacteriuria in pregnancy
Infection	Bateriuria	791.9	Bacteriuria
Infection	Systemic infection	486	Pneumonia organism unspecified
Infection	Systemic infection	540.X	Acute appendicitis
Infection	Systemic infection	590.XX	Pyelonephritis or infection of kidney unspecified
Infection	Other infections	041.0X	Streptococcus infection
Infection	Other infections	041.5	Hemophilus influenzae (H. influenzae) infection in conditions classified elsewhere and of unspecified site
Infection	Other infections	041.8X	Other specified bacterial infections
Infection	Other infections	042.XX	Human immunodeficiency virus (HIV)
Infection	Other infections	052.XX	Chickenpox
Infection	Other infections	053.XX	Herpes zoster
Infection	Other infections	054.XX	Herpes simplex
Infection	Other infections	056.XX	Rubella
Infection	Other infections	070	Viral hepatitis
Infection	Other infections	070.0	Viral hepatitis a with hepatic coma
Infection	Other infections	070.1	Viral hepatitis a without hepatic coma
Infection	Other infections	070.2	Viral hepatitis b with hepatic coma
Infection	Other infections	070.20	Viral hepatitis b with hepatic coma acute or unspecified without hepatitis delta
Infection	Other infections	070.21	Viral hepatitis b with hepatic coma acute or unspecified with hepatitis delta
Infection	Other infections	070.3	Viral hepatitis b without mention of hepatic coma
Infection	Other infections	070.30	Viral hepatitis b without hepatic coma acute or unspecified without hepatitis delta
Infection	Other infections	070.31	Viral hepatitis b without hepatic coma acute or unspecified with hepatitis delta
Infection	Other infections	075.XX	Infectious mononucleosis
Infection	Other infections	078.5	Cytomegaloviral disease
Infection	Other infections	079.53	Human immunodeficiency virus type 2 [HIV-2]
Infection	Other infections	079.83	Parvovirus b19
Infection	Other infections	090.XX	Congenital syphilis
Infection	Other infections	091.XX	Syphilis
Infection	Other infections	092.XX	Early syphilis, latent
Infection	Other infections	093.XX	Cardiovascular syphilis
Infection	Other infections	094.XX	Neurosyphilis
Infection	Other infections	095.XX	Other forms of syphilis with symptoms
Infection	Other infections	096.XX	Late syphilis, latent
Infection	Other infections	097.XX	Other and unspecified late syphilis
Infection	Other infections	098.XX	Gonococcal infection
Infection	Other infections	099.XX	Venereal disease due to chlamydia
Infection	Other infections	130.XX	Toxoplasmosis
Infection	Other infections	131.XX	Trichomoniasis
Infection	Other infections	599.0	Urinary tract infection site not specified
Infection	Other infections	616.1X	Bacterial vaginosis
Infection	Other infections	646.6X	Infections of genitourinary tract
Infection	Other infections	647.60	Other viral diseases of mother complicating pregnancy childbirth or the puerperium unspecified as to episode of care
Infection	Other infections	647.61	Other viral diseases of mother with delivery
Infection	Other infections	647.62	Other viral diseases of mother with delivery with postpartum complication
Infection	Other infections	647.63	Other antepartum viral diseases
Infection	Other infections	647.64	Other postpartum viral diseases
Infection	Other infections	771.1	Congenital cytomegalovirus infection
Infection	Other infections	795.71	Nonspecific serologic evidence of human immunodeficiency virus (HIV)
Infection	Other infections	V08	Asymptomatic human immunodeficiency virus (HIV) infection status
Prior obstetric history	Cervical shortening	649.7X	Cervical shortening
Prior obstetric history	Previous preterm labor	V23.41	Pregnancy with history of pre-term labor
Prior obstetric history	Poor obstetric history	V23.49	Pregnancy with other poor obstetric history
Prior obstetric history	Poor obstetric history	V23.5	Supervision of high-risk pregnancy with other poor obstetric history
Obstetric complication	Hemorrhage	656.00	Fetal-maternal hemorrhage unspecified as to episode of care in pregnancy
Obstetric complication	Hemorrhage	656.01	Fetal-maternal hemorrhage with delivery
Obstetric complication	Hemorrhage	656.03	Fetal-maternal hemorrhage antepartum condition or complication
Obstetric complication	Premature rupture of membranes	658.1X	Premature rupture of membranes
Obstetric complication	Premature rupture of membranes	658.20	Delayed delivery after spontaneous or unspecified rupture of membranes unspecified as to episode of care
Obstetric complication	Premature rupture of membranes	658.21	Delayed delivery after spontaneous or unspecified rupture of membranes delivered
Obstetric complication	Premature rupture of membranes	658.23	Delayed delivery after spontaneous or unspecified rupture of membranes antepartum
Fetal complication	Polyhydramnios	657.XX	Polyhydramnios
Fetal complication	Fetal growth	656.50	Poor fetal growth affecting management of mother unspecified as to episode of care
Fetal complication	Fetal growth	656.51	Poor fetal growth affecting management of mother delivered
Fetal complication	Fetal growth	656.53	Poor fetal growth affecting management of mother and antepartum condition or complication
Behavioral factors	Substance use	303.XX	Acute alcoholic intoxication or other and unspecified alcohol dependence
Behavioral factors	Substance use	304.XX	Drug dependence
Behavioral factors	Substance use	305.XX	Nondependent abuse of drugs
Behavioral factors	Substance use	648.33	Antepartum drug dependence
Behavioral factors	Substance use	649.0X	Tobacco use disorder complicating pregnancy, childbirth, or the puerperium
Psychosocial factors	Mental health condition	290.1X	Presenile dementia
Psychosocial factors	Mental health condition	290.4X	Vascular dementia
Psychosocial factors	Mental health condition	291.XX	Alcohol withdrawal and alcohol-induced mental disorders
Psychosocial factors	Mental health condition	292.XX	Drug withdrawal and drug-induced mental disorders
Psychosocial factors	Mental health condition	293.XX	Delirium and psychotic, mood, anxiety and transient mental disorders
Psychosocial factors	Mental health condition	294.XX	Amnestic disorder, dementia, and other persistent mental disorders
Psychosocial factors	Mental health condition	295.XX	Schizophrenia
Psychosocial factors	Mental health condition	296.XX	Bipolar, manic affective, major depressive and episodic mood disorders
Psychosocial factors	Mental health condition	297.X	Paranoid state, delusional, paraphrenia and shared psychotic disorders
Psychosocial factors	Mental health condition	298.X	Depressive type psychosis, excitative type psychosis, reactive confusion, acute paranoid reaction, psychogenic paranoid psychosis, other and unspecified reactive psychosis and unspecified psychosis
Psychosocial factors	Mental health condition	299.XX	Autistic disorder, childhood disintegrative disorder, other or unspecified pervasive developmental disorder
Psychosocial factors	Mental health condition	300.XX	Anxiety state unspecified, panic disorder without agoraphobia, generalized anxiety disorder, other anxiety states, hysteria unspecified, conversion disorder, dissociative amnesia, dissociative fugue, dissociative identity disorder, dissociative disorder or reaction unspecified, factitious disorder with predominantly psychological signs and symptoms, other and unspecified factitious illness, phobia unspecified, agoraphobia with panic disorder, agoraphobia without panic attacks, social phobia, other isolated or specific phobias, obsessive-compulsive disorders, dysthymic disorder, neurasthenia, depersonalization disorder, hypochondriasis, somatization disorder, undifferentiated somatoform disorder, other somatoform disorders, unspecified nonpsychotic mental disorder
Psychosocial factors	Mental health condition	301.XX	Paranoid personality disorder, affective personality disorder unspecified, chronic hypomanic personality disorder, chronic depressive personality disorder, cyclothymic disorder, schizoid personality disorder unspecified, introverted personality, schizotypal personality disorder, explosive personality disorder, obsessive-compulsive personality disorder, histrionic personality disorder unspecified, chronic factitious illness with physical symptoms, other histrionic personality disorder, dependent personality disorder, antisocial personality disorder, narcissistic personality disorder, avoidant personality disorder, borderline personality disorder, passive-aggressive personality, other personality disorders, unspecified personality disorder
Psychosocial factors	Mental health condition	302.XX	Unspecified psychosexual disorder
Psychosocial factors	Mental health condition	317	Mild intellectual disabilities
Psychosocial factors	Mental health condition	318.X	Moderate, severe and profound intellectual disabilities
Psychosocial factors	Mental health condition	319	Unspecified intellectual disabilities
Psychosocial factors	Mental health condition	648.4X	Mental disorders of mother
Prenatal care	Prenatal care	V22.0	Healthy prenatal visit
Prenatal care	Prenatal care	V22.1	Healthy prenatal visit
Prenatal care	Prenatal care	V22.2	Healthy prenatal visit
Prenatal care	Prenatal care	V23.XX	High risk prenatal visit

Table A.4:

ICD-9 Codes for Preterm Birth Phenotypes

Phenotype	Code	Code Description	Code Type
Spontaneous	658.1X	Premature rupture of membranes	ICD-9-CM
Spontaneous	658.20	Delayed delivery after spontaneous or unspecified rupture of membranes unspecified as to episode of care	ICD-9-CM
Spontaneous	658.21	Delayed delivery after spontaneous or unspecified rupture of membranes delivered	ICD-9-CM
Spontaneous	658.23	Delayed delivery after spontaneous or unspecified rupture of membranes antepartum	ICD-9-CM
Spontaneous	644.X	Early or threatened labor	ICD-9-CM
Medically Indicated	73.01	Induction of labor by artificial rupture of membranes	ICD-9-CM (procedure)
Medically Indicated	73.09	Other artificial rupture of membranes	ICD-9-CM (procedure)
Medically Indicated	73.1	Other surgical induction of labor	ICD-9-CM (procedure)
Medically Indicated	73.4	Medical induction of labor	ICD-9-CM (procedure)
Medically Indicated	74	Classical cesarean section convert	ICD-9-CM (procedure)
Medically Indicated	74.1	Low cervical cesarean section convert	ICD-9-CM (procedure)
Medically Indicated	74.2	Extraperitoneal cesarean section convert	ICD-9-CM (procedure)
Medically Indicated	74.3	Removal of extratubal ectopic pregnancy convert	ICD-9-CM (procedure)

Figure B.1.

Flowchart of Inclusion/Exclusion Criteria

Flowchart is based on CDM SES dataset version.

Table B.1.

Overlapping Summary Statistics for Pregnancy Cohorts from CDM ZIP5 Version

Characteristics	Continuous Enrollment n = 886,333	ACOG Screen (Non-Fasting) n= 210,274	Complete ACOG OGTT n = 33,603	Complete ADA OGTT n = 11,603
Maternal Age (years)	(%)	(%)	(%)	(%)
≤24	11.3	8.5	4.4	6.5
25-29	26.2	24.3	20.6	21.2
30-34	40.0	42.0	43.0	42.9
≥35	30.9	32.3	38.6	35.2
Clinical Covariates
Prenatal Care within 5 Months	83.0	81.8	81.6	82.1
Gestational Diabetes	15.4	17.2	56.6	44.8
Obesity	10.3	12.3	17.2	16.2
Infection	31.2	32.9	32.5	33.9
Mental Illness	10.6	10.3	10.8	9.8
Substance Use	4.1	3.2	3.5	3.2
Pregnancy Complications
Cervical Shortening	1.0	1.3	1.7	1.8
Premature Rupture of Membranes	7.5	7.5	8.2	7.4
Preeclampsia	15.1	15.4	19.2	17.1
Poor Fetal Growth	14.9	15.2	14.3	14.9
Gestational Age
24-27 weeks	0.9	0.3	0.2	0.4
28-31 weeks	0.6	0.4	0.5	0.4
32-33 weeks	9.4	8.2	9.4	9.5
34-36 weeks	97.6	98.2	96.4	95.4
37-42 weeks	0.9	0.3	0.2	0.4
Preterm birth type (<37 weeks)
Spontaneous	7.3	6.0	6.9	6.5
Medically-indicated	2.2	1.9	2.2	2.5
Unclassified	1.4	1.0	1.1	1.3

ACOG = American College of Obstetricians & Gynecologists; ADA = American Diabetes Association; OGTT = oral glucose tolerance test

Table B.2.

Distribution of Glucose Measures from CDM SES Version

Characteristics	Average (SD)	Median	Minimum	1st Quartile	3rd Quartile	Maximum
ACOG, 50-g, Non-Fasting Screen	117.9 (29.1)	115	57	96	139	211
ACOG, 100-g, Fasting	80.9 (9.9)	79	55	75	85	235
ACOG, 100-g, 1-hour post-load	162.6 (29.1)	162	78	143	182	252
ACOG, 100-g, 2-hour post-load	140.2 (28.8)	139	67	120	159	240
ACOG, 100-g, 3-hour post-load	108.8 (28.2)	109	39	90	127	198
ADA, 75-g, Fasting	79.7 (9.1)	78	55	74	84	194
ADA, 75-g, 1-hour post-load	147.9 (32.9)	148	67	125	171	241
ADA, 75-g, 2-hour post-load	124.9 (31.1)	123	57	102	145	234

SD = standard deviation; ACOG = American College of Obstetricians & Gynecologists; ADA = American Diabetes Association; OGTT = oral glucose tolerance test

Table B.3.

Unadjusted and Adjusted Poisson Regression Results for Preterm Birth (<37 weeks) (CDM ZIP5 Version)

Glucose Measurement	Overall Unadjusted RR (95%CI)	Overall Adjusted RR (95%CI)
ACOG, 50-g, Non-Fasting Screen	1.18 (1.16, 1.20)	1.18 (1.16, 1.20)
ACOG, 100-g, Fasting	1.08 (1.05, 1.12)	1.07 (1.03, 1.10)
ACOG, 100-g, 1-hour post-load	1.12 (1.08, 1.16)	1.12 (1.08, 1.16)
ACOG, 100-g, 2-hour post-load	1.15 (1.11, 1.19)	1.15 (1.11, 1.19)
ACOG, 100-g, 3-hour post-load	1.10 (1.06, 1.14)	1.10 (1.06, 1.14)
ADA, 75-g, Fasting	1.07 (1.01, 1.13)	1.05 (0.99, 1.11)
ADA, 75-g, 1-hour post-load	1.17 (1.10, 1.24)	1.13 (1.06, 1.20)
ADA, 75-g, 2-hour post-load	1.20 (1.13, 1.27)	1.16 (1.09, 1.23)

RR are calculated for an increase of 1 SD from the mean for each glucose measurement. Models were adjusted for maternal age, Area Deprivation Index quartile, US Census region, obesity, infection, mental illness, substance use, cervical shortening, and prenatal care. The CDM ZIP5 dataset version was used.

Table B.4.

Adjusted Poisson Regression Results for Preterm Birth Stratified by Gestational Diabetes Status

	Overall Adjusted RR (95%CI)	With Gestational Diabetes RR (95%CI)	Without Gestational Diabetes RR (95%CI)
ACOG, 50-g, Non-Fasting Screen	1.18 (1.16, 1.20)	1.17 (1.12, 1.22)	1.17 (1.15, 1.20)
ACOG, 100-g, Fasting	1.07 (1.04, 1.11)	1.09 (1.05, 1.13)	1.01 (0.93, 1.08)
ACOG, 100-g, 1-hour post-load	1.13 (1.09, 1.17)	1.12 (1.07, 1.18)	1.12 (1.04, 1.21)
ACOG, 100-g, 2-hour post-load	1.15 (1.11, 1.19)	1.14 (1.09, 1.19)	1.15 (1.06, 1.24)
ACOG, 100-g, 3-hour post-load	1.11 (1.07, 1.15)	1.09 (1.04, 1.14)	1.12 (1.05, 1.20)
ADA, 75-g, Fasting	1.05 (0.99, 1.12)	1.00 (0.93, 1.08)	0.99 (0.86, 1.14)
ADA, 75-g, 1-hour post-load	1.15 (1.08, 1.23)	0.99 (0.90, 1.09)	1.20 (1.06, 1.36)
ADA, 75-g, 2-hour post-load	1.19 (1.12, 1.27)	1.09 (1.00, 1.19)	1.23 (1.07, 1.41)

Models were adjusted in a similar manner described in Table 2. The CDM SES dataset version was used.

Table B.5.

Adjusted Poisson Regression Results for Preterm Birth Stratified by Preeclampsia Status

Glucose Measurement	Overall Adjusted RR (95%CI)	Yes Preeclampsia RR (95%CI)	No Preeclampsia RR (95%CI)
ACOG, 50-g, Non-Fasting Screen	1.18 (1.16, 1.20)	1.10 (1.07, 1.14)	1.17 (1.15, 1.19)
ACOG, 100-g, Fasting	1.07 (1.04, 1.11)	1.00 (0.95, 1.06)	1.08 (1.04, 1.13)
ACOG, 100-g, 1-hour post-load	1.13 (1.09, 1.17)	1.11 (1.04, 1.18)	1.12 (1.07, 1.17)
ACOG, 100-g, 2-hour post-load	1.15 (1.11, 1.19)	1.13 (1.06, 1.20)	1.14 (1.09, 1.19)
ACOG, 100-g, 3-hour post-load	1.11 (1.07, 1.15)	1.09 (1.02, 1.16)	1.13 (1.08, 1.18)
ADA, 75-g, Fasting	1.05 (0.99, 1.12)	0.93 (0.83, 1.04)	1.06 (0.98, 1.14)
ADA, 75-g, 1-hour post-load	1.15 (1.08, 1.23)	1.01 (0.90, 1.14)	1.18 (1.09, 1.27)
ADA, 75-g, 2-hour post-load	1.19 (1.12, 1.27)	1.10 (1.00, 1.23)	1.20 (1.11, 1.29)

Models were adjusted in a similar manner described in Table 2, except with the removal preeclampsia status. The CDM SES dataset version was used.

Table B.6.

Adjusted Poisson Regression Results for Preterm Birth Stratified by Maternal Age

Glucose Measurement	Overall Adjusted RR (95%CI)	Under 25 years RR (95%CI)	25 to 34 years RR (95%CI)	Over 35 years RR (95%CI)
ACOG, 50-g, Non-Fasting Screen	1.18 (1.16, 1.20)	1.10 (1.04, 1.16)	1.19 (1.16, 1.21)	1.19 (1.16, 1.22)
ACOG, 100-g, Fasting	1.07 (1.04, 1.11)	1.06 (0.91, 1.24)	1.06 (1.02, 1.11)	1.09 (1.04, 1.15)
ACOG, 100-g, 1-hour post-load	1.13 (1.09, 1.17)	1.28 (1.08, 1.53)	1.12 (1.07, 1.18)	1.12 (1.06, 1.19)
ACOG, 100-g, 2-hour post-load	1.15 (1.11, 1.19)	1.18 (1.00, 1.38)	1.13 (1.08, 1.19)	1.16 (1.09, 1.22)
ACOG, 100-g, 3-hour post-load	1.11 (1.07, 1.15)	1.04 (0.88, 1.24)	1.15 (1.10, 1.21)	1.07 (1.01, 1.13)
ADA, 75-g, Fasting	1.05 (0.99, 1.12)	1.13 (0.89, 1.43)	1.10 (1.02, 1.18)	0.94 (0.83, 1.05)
ADA, 75-g, 1-hour post-load	1.15 (1.08, 1.23)	1.14 (0.88, 1.48)	1.15 (1.05, 1.25)	1.17 (1.05, 1.30)
ADA, 75-g, 2-hour post-load	1.19 (1.12, 1.27)	1.33 (1.06, 1.67)	1.16 (1.07, 1.26)	1.22 (1.11, 1.35)

Models were adjusted in a similar manner described in Table 2, except with the removal of maternal age. The CDM SES dataset version was used.

Table B.7.

Adjusted Poisson Regression Results for Preterm Birth Stratified by Maternal Education Level

Glucose Measurement	Overall Adjusted RR (95%CI)	High School Diploma or Less RR (95%CI)	Less than Bachelor Degree RR (95%CI)	Bachelor Degree or More RR (95%CI)
ACOG, 50-g, Non-Fasting Screen	1 18 (1 16 1.20)	1 19 (1 15 1.23)	1 19 (1 16 1.21)	1 17 (1 13 1.21)
ACOG, 100-g, Fasting	1.07 (1.04, 1.11)	1.03 (0.96, 1.11)	1.10 (1.05, 1.14)	1.06 (0.98, 1.14)
ACOG, 100-g, 1-hour post-load	1.13 (1.09, 1.17)	1.18 (1.09, 1.29)	1.13 (1.08, 1.19)	1.08 (1.00, 1.16)
ACOG, 100-g, 2-hour post-load	1.15 (1.11, 1.19)	1.14 (1.06, 1.23)	1.14 (1.08, 1.20)	1.18 (1.09, 1.27)
ACOG, 100-g, 3-hour post-load	1.11 (1.07, 1.15)	1.03 (0.95, 1.12)	1.11 (1.06, 1.16)	1.20 (1.11, 1.30)
ADA, 75-g, Fasting	1.05 (0.99, 1.12)	1.00 (0.88, 1.12)	1.07 (0.99, 1.17)	1.05 (0.89, 1.24)
ADA, 75-g, 1-hour post-load	1.15 (1.08, 1.23)	1.10 (0.97, 1.26)	1.14 (1.04, 1.24)	1.24 (1.08, 1.43)
ADA, 75-g, 2-hour post-load	1.19 (1.12, 1.27)	1.20 (1.06, 1.36)	1.17 (1.08, 1.27)	1.21 (1.06, 1.39)

Models were adjusted in a similar manner described in Table 2, except with the removal of maternal education level. The CDM SES dataset version was used.

Table B.8.

Adjusted Poisson regression results for preterm birth stratified by maternal race/ethnicity

Glucose measurement	Overall adjusted RR (95%CI)	White (Non-Hispanic) RR (95%CI)	Black (Non-Hispanic) RR (95%CI)	Hispanic (All) RR (95%CI)	Asian RR (95%CI)
ACOG, 50-g, Non-fasting screen	1.18 (1.16, 1.20)	1.19 (1.17, 1.21)	1.16 (1.11, 1.22)	1.21 (1.17, 1.25)	1.11 (1.05, 1.17)
ACOG, 100-g, Fasting	1.07 (1.04, 1.11)	1.09 (1.04, 1.13)	1.06 (0.95, 1.18)	1.05 (0.98, 1.13)	1.06 (0.94, 1.19)
ACOG, 100-g, 1-hour post-load	1.13 (1.09, 1.17)	1.14 (1.08, 1.20)	1.16 (1.04, 1.30)	1.15 (1.05, 1.26)	1.04 (0.93, 1.16)
ACOG, 100-g, 2-hour post-load	1.15 (1.11, 1.19)	1.17 (1.12, 1.23)	1.10 (0.99, 1.23)	1.16 (1.07, 1.26)	1.06 (0.95, 1.18)
ACOG, 100-g, 3-hour post-load	1.11 (1.07, 1.15)	1.10 (1.05, 1.15)	1.08 (0.97, 1.20)	1.18 (1.09, 1.29)	1.13 (1.01, 1.26)
ADA, 75-g, Fasting	1.05 (0.99, 1.12)	1.12 (1.02, 1.22)	0.90 (0.76, 1.07)	1.07 (0.95, 1.20)	0.95 (0.77, 1.17)
ADA, 75-g, 1-hour post-load	1.15 (1.08, 1.23)	1.07 (0.98, 1.17)	1.04 (0.87, 1.23)	1.28 (1.13, 1.46)	1.44 (1.20, 1.73)
ADA, 75-g, 2-hour post-load	1.19 (1.12, 1.27)	1.16 (1.06, 1.26)	1.20 (1.03, 1.40)	1.24 (1.10, 1.41)	1.27 (1.08, 1.50)

Models were adjusted in a similar manner described in Table 2, except with the removal of maternal race/ethnicity. The CDM SES dataset version was used.

Table B.9.

Adjusted Poisson Regression Results for Preterm Birth Stratified by US Census Region

Glucose Measurement	Overall Adjusted RR (95%CI)	West RR (95%CI)	Midwest RR (95%CI)	South RR (95%CI)	Northeast RR (95%CI)
ACOG, 50-g, Non-Fasting Screen	1.18 (1.16, 1.20)	1.15 (1.11, 1.19)	1.20 (1.14, 1.25)	1.19 (1.17, 1.21)	1.17 (1.11, 1.23)
ACOG, 100-g, Fasting	1.07 (1.03, 1.10)	1.06 (0.97, 1.14)	1.10 (0.98, 1.24)	1.07 (1.03, 1.12)	1.01 (0.90, 1.13)
ACOG, 100-g, 1-hour post-load	1.12 (1.08, 1.16)	1.07 (0.98, 1.16)	1.18 (1.04, 1.34)	1.13 (1.08, 1.18)	1.11 (0.99, 1.24)
ACOG, 100-g, 2-hour post-load	1.15 (1.11, 1.19)	1.13 (1.04, 1.22)	1.16 (1.03, 1.31)	1.15 (1.10, 1.20)	1.19 (1.07, 1.32)
ACOG, 100-g, 3-hour post-load	1.10 (1.06, 1.14)	1.05 (0.96, 1.14)	1.03 (0.91, 1.16)	1.11 (1.06, 1.16)	1.16 (1.05, 1.30)
ADA, 75-g, Fasting	1.05 (0.99, 1.11)	0.94 (0.83, 1.07)	1.18 (1.03, 1.36)	1.06 (0.98, 1.15)	1.03 (0.75, 1.41)
ADA, 75-g, 1-hour post-load	1.13 (1.06, 1.20)	1.23 (1.10, 1.38)	1.25 (1.02, 1.53)	1.04 (0.96, 1.14)	1.28 (0.97, 1.68)
ADA, 75-g, 2-hour post-load	1.16 (1.09, 1.23)	1.23 (1.10, 1.37)	1.36 (1.13, 1.64)	1.09 (1.00, 1.18)	1.22 (0.94, 1.59)

Models were adjusted in a similar manner described in Table B.3, except with the removal of US Census region. The CDM ZIP5 dataset version was used.

Table B.10.

Approximate Significance of Generalized Additive Model Smoothed Terms of Various Glucose Measures

Glucose Measurement	Estimated Degrees of Freedom	Chi-Squared Statistic	P value
ACOG, 50-g, Non-Fasting Screen	2.54	495.1	<0.001
ACOG, 100-g, Fasting	4.74	29.1	<0.001
ACOG, 100-g, 1-hour post-load	1.01	37.5	<0.001
ACOG, 100-g, 2-hour post-load	1.01	61.1	<0.001
ACOG, 100-g, 3-hour post-load	2.98	37.8	<0.001
ADA, 75-g, Fasting	4.54	13.4	0.035
ADA, 75-g, 1-hour post-load	2.76	16.8	0.002
ADA, 75-g, 2-hour post-load	2.79	26.2	<0.001

Models were adjusted in a similar manner described in Table B.3. The CDM ZIP5 dataset version was used.