Abstract
Objective
This study aims to identify risk factors for prolonged postpartum length of stays (LOS) after cesarean delivery (CD).
Study Design
Patients undergoing CD were sourced from a multicenter registry of 19 academic centers between 1999 and 2002 (n = 57,067). Prolonged postpartum LOS was defined as a hospitalization duration ≥ 90th centile. Maternal, antepartum, perioperative, and neonatal variables were compared between women with and without prolonged postpartum LOS.
Results
The 90th centile for postpartum LOS was 4 days, with 14,954 women experiencing prolonged postpartum LOS. Women with perioperative complications had the highest independent risk for a prolonged postpartum LOS: ileus (adjusted odds ratio [aOR] = 12.28; 95% confidence interval CI = 8.98–16.8); endometritis (aOR = 10.45; 95% CI = 9.51–11.5), and wound complications (aOR = 5.49; 95% CI = 4.54–6.63). Several antepartum, perioperative, and neonatal variables were associated with a prolonged postpartum LOS.
Conclusion
Perioperative complications had the highest risk for prolonged LOS after CD. Strategies to reduce perioperative complications are needed to decrease the health care burden of prolonged post-CD LOS.
Keywords: cesarean, postpartum length of stay, prolonged
Cesarean delivery is one of the most common surgeries performed in the United States. In 2012, over 1.2 million cesarean deliveries were performed, accounting for 32.8% of all deliveries.1 Cesarean delivery has been implicated as an important explanatory factor for increasing rates of maternal morbidity, which includes venous thromboembolism, shock, and hemorrhage.2 As a consequence, multiple large-scale initiatives have been promoted by leading obstetric figures and organizations to reduce rates of maternal morbidity.3–5
Postoperative length of stay (LOS) after nonobstetric surgery has been identified as an important quality indicator of inpatient care.6–8 LOS after cesarean delivery may also be an important metric for evaluating the quality of peripartum and postpartum obstetric care. Unfortunately, studies investigating risk factors associated with prolonged LOS after a cesarean delivery are lacking. Such data could assist ongoing efforts aimed at reducing maternal morbidity after cesarean delivery and could be useful for evaluating postcesarean LOS as a quality measure related to obstetric practice.
The primary aim of this study was to identify risk factors for prolonged postpartum LOS after cesarean delivery. Moreover, we sought to analyze the contribution of potentially modifiable risk factors on prolonged LOS to highlight areas where improvements in perioperative care could be made. We also performed a secondary analysis to identify risk factors for prolonged LOS for the entire delivery hospitalization period including the intrapartum period.
Patients and Methods
The study cohort was identified using a dataset (the Cesarean registry) sourced from a previous multicenter study by the National Institute of Child Health and Human Development Maternal-Fetal Medicine Units (MFMU) Network.9 Briefly, between 1999 and 2002, data were collected in women who underwent primary cesarean delivery, repeat cesarean delivery, or trial of labor after cesarean, and who delivered infants ≥ 20 weeks or ≥ 500 g at 19 academic centers. The final 2 years of the study included only women who underwent repeat cesarean delivery or vaginal birth after cesarean. Data were collected through detailed chart review at delivery, and information regarding perioperative morbidity was collected from discharge summaries. Patients and hospitals were deidentified by the MFMU.
For the current study, we included only women from the Cesarean registry who had undergone a primary or repeat cesarean delivery. Based on a definition described by Kuklina et al,2 we defined a prolonged postpartum LOS as a postpartum hospitalization (number of hospital days between cesarean delivery to hospital discharge) with a postpartum LOS ≥ 90th centile. In the Cesarean registry dataset, all dates were expressed as day numbers. Maternal demographic, antepartum, perioperative, and neonatal variables were compared between women with and without prolonged LOS. Maternal characteristics included: age, race/ethnicity, body mass index (BMI) at delivery, diabetes, chronic hypertension, and number of prior cesarean deliveries. Obstetric variables included: gestational age at delivery, pregnancy-associated hypertension, labor, or induction before the cesarean delivery, and chorioamnionitis. Perioperative variables included: type of uterine incision, mode of anesthesia, intraoperative red blood cell transfusion, hysterectomy, and postpartum complications, such as endometritis and wound complications. We also compared birth weights of neonates of women with versus without prolonged LOS.
We performed bivariate analyses to compare maternal, obstetric, and neonatal characteristics between women with and without prolonged LOS after cesarean delivery. Categorical variables were compared using the chi-square test; bivariate analyses did not account for missing data. Based on bivariate analyses, unadjusted odds ratios (ORs) and accompanying 95% confidence intervals (CIs) were calculated. Candidate variables that were associated with prolonged LOS on bivariate analyses (p ≤ 0.1) were included as covariates in an unconditional multivariable logistic regression model. The final model was determined using a traditional backward elimination, with all variables initially included and then selectively removed if not significant (p < 0.05). To determine the presence of collinearity between independent variables, variance inflation factor (VIF) testing was performed. Collinearity was determined to be insignificant as VIF scores ranged from 1.01 to 1.49 with a mean VIF score of 1.18. Population attributable fractions (PAFs) were used to calculate the proportional reduction in risk of prolonged LOS that would occur by eliminating the exposure of interest from the population while the distribution of other risk factors remained unchanged. PAFs were calculated for selected risk factors that were considered modifiable by using adjusted ORs (aORs) from the final multivariate model.10 We calculated the area under the receiver-operating characteristic curve (AUROC) using standard methodology to assess the predictive performance of the final model.
Based on data for the date of hospital admission and discharge, we performed a secondary analysis to assess risk factors for prolonged total length of hospital stay, defined as the interval from admission to discharge. For the total period of hospital stay we defined a prolonged delivery hospitalization as a total hospital LOS ≥ 90th centile. We did not count the day of admission in the calculation for the total hospital LOS.
Data analyses were performed using SAS 9.2 (SAS Inc., Cary, NC) and STATA version 12 (Statacorp, College Station, TX). As the Cesarean registry contains deidentified data, our study was deemed institutional review board exempt by the Stanford Institutional Review Board.
Results
A total of 57,812 women underwent primary or repeat cesarean delivery in the MFMU Cesarean registry. We excluded 79 women with missing LOS data, and 36 women who died during their hospitalization. The median (interquartile range [IQR]) postpartum LOS after cesarean delivery was 3 days (3–4 days). The 90th centile for the postpartum LOS was 4 days and 14,954 women were identified with a prolonged postpartum LOS.
Maternal sociodemographic and antepartum characteristics were compared between women with and without prolonged LOS (Table 1). Compared with women with a postpartum LOS < 4 days, women with prolonged postpartum LOS were more likely to have the following characteristics: aged < 20 years or > 34 years, non-Hispanic race/ethnicity, private or government-assisted insurance, BMI ≤ 24.9 or ≥ 40, medical comorbidity (preexisting diabetes; chronic hypertension; asthma), obstetric comorbidity (pregnancy-related hypertension, placenta previa, preterm delivery), and multiple pregnancy (Table 1). On bivariate analyses, compared with women with no prior cesarean deliveries, women with one cesarean or two or more prior cesareans were less likely to have prolonged postpartum LOS (Table 1).
Table 1.
Maternal demographic and antepartum data by postpartum and total hospital length of stay
| Postpartum LOS < 4 d (n = 42,113) | Postpartum LOS ≥ 4 d (n = 14,954) | p-Value | Total hospital LOS < 6 d (n = 50,945) | Total hospital LOS ≥ 6 d (n = 6,122) | p-Value | |
|---|---|---|---|---|---|---|
| Maternal demographics | ||||||
| Maternal age (y) | < 0.001 | < 0.001 | ||||
| < 20 | 2,925 (6.9%) | 1,242 (8.3%) | 3,470 (6.8%) | 697 (11.4%) | ||
| 20–34 | 30,107 (71.5%) | 9,665 (64.6%) | 35,783 (70.3%) | 3,989 (65.2%) | ||
| > 34 | 8,890 (21.1%) | 3,894 (26.1%) | 11,423 (22.4%) | 1,361 (22.2%) | ||
| Missing | 191 (0.5%) | 153 (1.0%) | 269 (0.5%) | 75 (1.2%) | ||
| Insurance status | < 0.001 | < 0.001 | ||||
| Government-assisted | 16,632 (39.5%) | 6,145 (41.1%) | 19,906 (39.1%) | 2,871 (46.9%) | ||
| Private insurance | 16,938 (40.2%) | 6,860 (45.9%) | 21,680 (42.6%) | 2,118 (34.6%) | ||
| Self-pay/other | 6,260 (14.9%) | 1,362 (9.1%) | 6,887 (13.5%) | 735 (12.0%) | ||
| Missing | 2,283 (5.4%) | 587 (3.9%) | 2,472 (4.8%) | 398 (6.5%) | ||
| Race | < 0.001 | < 0.001 | ||||
| Caucasian | 16,666 (39.6%) | 6,227 (41.6%) | 20,790 (40.8%) | 2,103 (34.4%) | ||
| African American | 10,756 (25.5%) | 5,142 (34.4%) | 13,404 (26.3%) | 2,494 (40.7%) | ||
| Hispanic | 12,688 (30.1%) | 2,710 (18.1%) | 14,180 (27.8%) | 1,218 (19.9%) | ||
| Other | 2,003 (4.8%) | 875 (5.9%) | 2,571 (5.1%) | 307 (5%) | ||
| BMI at delivery (kg/m2) | < 0.001 | < 0.001 | ||||
| ≤ 24.9 | 3,526 (8.4%) | 1,380 (9.2%) | 4,182 (8.2%) | 724 (11.8%) | ||
| 25–29.9 | 11,597 (27.5%) | 3,988 (26.7%) | 14,141 (27.8%) | 1,444 (23.6%) | ||
| 30–34.9 | 11,982 (28.4%) | 3,945 (26.4%) | 14,502 (28.5%) | 1,425 (23.3%) | ||
| 35–39.9 | 6,822 (16.2%) | 2,368 (15.8%) | 8,204 (16.1%) | 986 (16.1%) | ||
| ≥ 40 | 5,627 (13.4%) | 2,445 (16.4%) | 6,993 (13.7%) | 1,079 (17.6%) | ||
| Missing | 2,559 (6.1%) | 828 (5.5%) | 2,923 (5.7%) | 464 (7.6%) | ||
| Preexisting maternal comorbidities | ||||||
| Preexisting diabetes | 3,815 (9.1%) | 1,749 (11.7%) | < 0.001 | 4,602 (8.1%) | 962 (15.7%) | < 0.001 |
| Chronic hypertension | 863 (2.1%) | 715 (4.8%) | < 0.001 | 1,109 (2.2%) | 469 (7.7%) | < 0.001 |
| Asthma | 2,854 (6.8%) | 1,347 (9.0%) | < 0.001 | 3,634 (7.1%) | 567 (9.3%) | < 0.001 |
| Antepartum variables | ||||||
| Gestational age at delivery (wks) | < 0.001 | < 0.001 | ||||
| < 37 | 6,648 (15.8%) | 4,983 (33.3%) | 7,754 (15.2%) | 3,877 (63.3%) | ||
| 37–41 | 31,924 (75.8%) | 8,963 (59.9%) | 38,955 (76.5%) | 1,932 (31.6%) | ||
| > 41 | 3,477 (8.3%) | 985 (6.6%) | 4,162 (8.2%) | 300 (4.9%) | ||
| Missing | 64 (0.1%) | 23 (0.2%) | 74 (0.1%) | 13 (0.2%) | ||
| Number of gestations | < 0.001 | < 0.001 | ||||
| Singleton pregnancy | 40,375 (96.7%) | 13,852 (92.6%) | 49,128 (96.4%) | 5,459 (89.2%) | ||
| Multiple pregnancy | 1,378 (3.3%) | 1,102 (7.4%) | 1,817 (3.6%) | 663 (10.8%) | ||
| Number of prior CD | < 0.001 | < 0.001 | ||||
| None | 16,333 (38.8%) | 6,870 (45.9%) | 19,512 (38.3%) | 3,691 (60.3%) | ||
| 1 prior CD | 17,917 (42.5%) | 5,637 (37.7%) | 21,869 (42.9%) | 1,685 (27.5%) | ||
| 2 or more prior CD | 7,698 (18.3%) | 2,380 (15.9%) | 9,372 (18.4%) | 706 (11.5%) | ||
| Missing | 165 (0.4%) | 67 (0.5%) | 192 (0.4%) | 40 (0.7%) | ||
| Pregnancy-associated hypertensiona | < 0.001 | < 0.001 | ||||
| None | 37,810 (89.8%) | 11,794 (78.9%) | 45,763 (89.8%) | 3,841 (62.8%) | ||
| Gestational hypertension | 1,366 (3.3%) | 588 (3.9%) | 1,649 (3.2%) | 305 (15.6%) | ||
| Preeclampsia | 2,752 (6.5%) | 2,241 (15.0%) | 3,244 (6.4%) | 1,749 (28.6%) | ||
| Eclampsia/HELLP syndrome | 181 (0.4%) | 329 (2.2%) | 284 (0.6%) | 226 (3.7%) | ||
| Placenta previa | 557 (1.3%) | 340 (2.3%) | < 0.001 | 541 (1.1%) | 356 (5.8%) | < 0.001 |
Abbreviations: BMI, body mass index; CD, cesarean delivery; HELLP, hemolysis, elevated liver enzymes, low platelets; LOS, length of stay.
Six patients missing data for pregnancy-associated hypertension.
We then compared perioperative and postpartum risk factors between those with and without a prolonged postpartum LOS (Table 2). Perioperative morbidities, including intraoperative transfusion, postpartum transfusion, hysterectomy, wound complications, maternal ileus, and endometritis, were more common among women with prolonged postpartum LOS. Women who delivered neonates with low birth weight (< 2,500 g) also had significantly higher rates of prolonged postpartum LOS compared with women who delivered infants between 2,500 and 3,499 g or neonates ≥ 3,500 g.
Table 2.
Perioperative, postpartum, and neonatal characteristics by postpartum and total hospital length of stay
| Postpartum LOS < 4 d (n = 42,113) | Postpartum LOS ≥ 4 d (n = 14,954) | p-Value | Total hospital LOS < 6 d (n = 50,945) | Total hospital LOS ≥ 6 d (n = 6,122) | p-Value | |
|---|---|---|---|---|---|---|
| Intrapartum factors | ||||||
| Labor or attempted induction | 19,771 (46.9%) | 7,413 (49.6%) | < 0.001 | 23,862 (46.8%) | 3,322 (5.8%) | < 0.001 |
| Placental abruption | 760 (1.8%) | 549 (3.7%) | <0.001 | 914 (1.8%) | 395 (6.4%) | <0.001 |
| Perioperative factors | ||||||
| Mode of anesthesia | < 0.001 | < 0.001 | ||||
| Neuraxial anesthesia | 39,467 (93.7%) | 13,054 (87.3%) | 47,538 (93.3%) | 4,983 (81.4%) | ||
| General anesthesia | 2,579 (6.1%) | 1,877 (12.6%) | 3,333 (6.5%) | 1,123 (18.3%) | ||
| Missing | 67 (0.2%) | 23 (0.1%) | 74 (0.2%) | 16 (0.3%) | ||
| Uterine atony | 1,517 (3.6%) | 944 (6.3%) | < 0.001 | 1,998 (3.9%) | 463 (7.6%) | < 0.001 |
| Hysterectomy at cesarean | 79 (0.2%) | 205 (1.4%) | < 0.001 | 160 (0.3%) | 124 (2%) | < 0.001 |
| Intraoperative RBC transfusion | 157 (0.4%) | 337 (2.3%) | < 0.001 | 274 (0.5%) | 220 (3.6%) | < 0.001 |
| Postpartum complications | ||||||
| Postpartum RBC transfusion | 409 (0.7%) | 779 (5.2%) | < 0.001 | 704 (1.4%) | 484 (7.9%) | < 0.001 |
| Wound complicationa | 195 (0.5%) | 540 (3.6%) | < 0.001 | 418 (0.82%) | 317 (5.2%) | < 0.001 |
| Ileus | 60 (0.1%) | 333 (2.2%) | < 0.001 | 189 (0.4%) | 204 (3.3%) | < 0.001 |
| Endometritis | 890 (2.1%) | 2,476 (16.6%) | < 0.001 | 1,921 (3.8%) | 1,445 (23.6%) | < 0.001 |
| Neonatal factors | ||||||
| Birth weight | <0.001 | <0.001 | ||||
| < 2,500 g | 5,193 (12.3%) | 4,068 (27.2%) | 5,845 (11.5%) | 3,416 (55.8%) | ||
| 2,500–3,499 g | 31,799 (75.5%) | 9,356 (62.6%) | 38,779 (76.1%) | 2,376 (38.8%) | ||
| ≥ 3,500 g | 5,101 (12.1%) | 1,518 (10.1%) | 6,296 (12.3%) | 323 (5.3%) | ||
| Missing | 20 (0.1%) | 12 (0.1%) | 25 (0.1%) | 7 (0.1%) | ||
Abbreviations: LOS, length of stay; RBC, red blood cells.
Wound complications include: infection, seroma, and hematoma.
Table 3 summarizes the crude and aORs of risk factors for prolonged postpartum LOS. Patients who experienced perioperative complications had the highest aOR for prolonged LOS: ileus (aOR = 12.28); endometritis (aOR = 10.45), wound complications (aOR = 5.49), hysterectomy during cesarean delivery (aOR = 3.16), and postpartum red blood cell (RBC) transfusion (aOR = 3.04). Among the obstetric morbidities included in our model, eclampsia/hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome had the highest risk of prolonged postpartum LOS (aOR = 2.65). For prolonged postpartum LOS, the PAFs for surgical complications were high (endometritis = 9.8% [95% CI = 9.4–10.2%]; ileus = 10.3% [95% CI = 9.5–11.3%]; and wound complications = 15.1% [95% CI = 13.5–16.7%].
Table 3.
Risk factors for prolonged postpartum and prolonged total length of stay
| Prolonged postpartum LOS | Prolonged total hospital LOS | |||
|---|---|---|---|---|
| Unadjusted OR (95% CI) | Adjusted OR (95% CI) | Unadjusted OR (95% CI) | Adjusted OR (95% CI) | |
| Demographic factors | ||||
| Maternal age (y) | ||||
| < 20 | 1.32 (1.23–1.42) | 1.03 (0.94–1.12) | 1.80 (1.65–1.97) | – |
| 20–34 | Referent | Referent | Referent | – |
| > 34 | 1.36 (1.31–1.43) | 1.31 (1.25–1.39) | 1.07 (1.00–1.14) | – |
| Insurance class | ||||
| Government-assisted | Referent | Referent | Referent | Referent |
| Private insurance | 1.10 (1.05–1.14) | 1.17 (1.11–1.23) | 0.68 (0.64–0.72) | 0.83 (0.77–0.90) |
| Self-pay/other | 0.59 (0.55–0.63) | 0.72 (0.66–0.78) | 0.74 (0.68–0.81) | 0.90 (0.80–1.01) |
| Race | ||||
| Caucasian | Referent | Referent | Referent | Referent |
| African American | 1.28 (1.22–1.34) | 1.08 (1.02–1.14) | 1.84 (1.73–19.6) | 1.33 (1.21–1.45) |
| Hispanic | 0.57 (0.54–0.60) | 0.64 (0.59–0.68) | 0.85 (0.79–0.91) | 1.03 (0.92–1.15) |
| Other | 1.17 (1.07–1.27) | 1.07 (0.97–1.19) | 1.18 (1.04–1.34) | 1.06 (0.89–1.25) |
| BMI at delivery (kg/m2) | ||||
| ≤ 24.9 | Referent | Referent | Referent | Referent |
| 25–29.9 | 0.88 (0.82–0.94) | 1.03 (0.95–1.13) | 0.59 (0.54–0.65) | 0.93 (0.82–1.05) |
| 30–34.9 | 0.84 (0.78–0.90) | 1.02 (0.93–1.10) | 0.57 (0.51–0.63) | 0.98 (0.86–1.10) |
| 35–39.9 | 0.89 (082–0.96) | 0.97 (0.88–1.06) | 0.69 (0.63–0.77) | 1.08 (0.95–1.24) |
| ≥ 40 | 1.11 (1.02–1.20) | 1.14 (1.04–1.25) | 0.89 (0.81–0.99) | 1.35 (1.18–1.55) |
| Preexisting maternal complications | ||||
| Preexisting diabetes | 1.33 (1.25–1.41) | 1.22 (1.13–1.31) | 1.88 (1.74–2.02) | 2.04 (1.85–2.27) |
| Chronic hypertension | 2.40 (2.17–2.66) | 1.28 (1.14–1.45) | 3.73 (3.34–4.17) | 1.21 (1.04–1.41) |
| Asthma | 1.36 (1.27–1.46) | 1.24 (1.15–1.34) | 1.33 (1.21–1.46) | – |
| Prenatal factors | ||||
| Gestational age at delivery (wk) | ||||
| < 37 | 2.67 (2.56–2.79) | 1.71 (1.59–1.84) | 10.08 (9.50–10.70) | 4.18 (3.77–4.63) |
| 37–41 | Referent | Referent | Referent | Referent |
| > 41 | 1.01 (0.94–1.09) | 0.96 (0.88–1.05) | 1.45 (1.28–1.65) | 1.19 (1.02–1.41) |
| Type of pregnancy | ||||
| Singleton pregnancy | Referent | Referent | Referent | – |
| Multiple pregnancy | 3.29 (2.99–3.61) | 1.49 (1.34–1.64) | 3.29 (2.99–3.61) | – |
| Number of prior CD | ||||
| None | Referent | Referent | Referent | Referent |
| 1 prior CD | 0.75 (0.72–0.78) | 1.08 (1.03–1.14) | 0.41 (0.38–0.43) | 0.67 (0.62–0.73) |
| 2 or more prior CD | 0.74 (0.70–0.78) | 1.09 (1.02–1.16) | 0.40 (0.37–0.43) | 0.62 (0.55–0.69) |
| Pregnancy-associated hypertension | ||||
| None | Referent | Referent | Referent | Referent |
| Gestational hypertension | 1.38 (1.25–1.52) | 1.29 (1.07–1.35) | 2.20 (1.94–2.50) | 1.98 (1.68–2.32) |
| Preeclampsia | 2.61 (2.46–2.77) | 1.82 (1.69–1.96) | 6.42 (6.00–6.87) | 2.99 (2.73–3.28) |
| Eclampsia/HELLP syndrome | 5.83 (4.85–6.99) | 2.65 (2.12–3.30) | 9.48 (7.94–11.33) | 2.05 (1.63–2.57) |
| Placenta Previa | 1.74 (1.51–1.99) | – | 5.75 (5.02–6.59) | 3.32 (2.74–3.28) |
| Intrapartum factors | ||||
| Labor or attempted induction | 1.11 (1.078–1.15) | – | 1.35 (1.28–1.42) | 1.12 (1.03–1.21) |
| Placental abruption | 2.08 (1.86–2.32) | – | 3.78 (3.35–4.26) | – |
| Perioperative factors | ||||
| Mode of anesthesia | ||||
| Neuraxial anesthesia | Referent | Referent | Referent | Referent |
| General anesthesia | 2.20 (2.07–2.34) | 1.30 (1.20–1.42) | 3.22 (2.99–3.46) | 1.12 (1.00–1.24) |
| Uterine atony | 1.80 (1.66–1.96) | 1.32 (1.19–1.46) | 2.01 (1.81–2.23) | 1.41 (1.21–1.63) |
| Hysterectomy at CD | 6.57 (5.19–8.31) | 3.16 (2.20–4.52) | 6.57 (5.19–8.31) | 2.02 (1.36–3.02) |
| Intraoperative RBC transfusion | 6.16 (5.09–7.45) | 1.76 (1.33–2.33) | 6.90 (5.76–8.25) | 1.57 (1.14–2.16) |
| Postpartum RBC transfusion | 5.60 (4.96–6.33) | 3.04 (2.59–3.57) | 6.13 (5.44–6.90) | 2.67 (2.22–3.21) |
| Wound complicationa | 8.05 (6.83–9.49) | 5.49 (4.54–6.63) | 6.60 (5.69–7.66) | 5.00 (4.02–6.21) |
| Ileus | 15.96 (12.11–21.02) | 12.28 (8.98–16.80) | 9.26 (7.58–11.30) | 9.28 (7.03–12.2) |
| Endometritis | 9.19 (8.49–9.95) | 10.45 (9.51–11.50) | 7.89 (7.32–8.50) | 9.81 (8.84–10.89) |
| Neonatal factors | ||||
| Birth weight | ||||
| Less than 2,500 g | 2.66 (2.54–2.79) | 1.22 (1.10–1.35) | 9.54 (8.99–10.12) | 3.57 (3.01–4.23) |
| 2,500–3,499 g | Referent | Referent | Referent | Referent |
| 3,500 g or more | 1.01 (0.95–1.07) | 0.92 (0.86–0.99) | 0.84 (0.74–0.94) | 1.14 (0.99–1.32) |
Abbreviations: BMI, body mass index; CD, cesarean delivery; CI, confidence interval; LOS, length of stay; OR, odds ratio; RBC, red blood cells.
Wound complications include: infection/seroma/hematoma.
Women whose insurance status was self-pay or other, who were Hispanic, or who had an infant with a birth weight ≥ 3,500 g were independently associated with a reduced risk of prolonged postpartum LOS. The final model yielded an AUROC of 0.72, which indicates moderate model discrimination.
In our secondary analysis, the median (IQR) period for total LOS was 3 days (3–4 days), and the 90th centile for the total LOS was 6 days. A total of 6,122 (10.6%) women were identified with a prolonged total LOS. Data for sociodemographic, antepartum, peripartum, and postpartum characteristics for women with and without prolonged total LOS are presented in Tables 1 and 2. Data from our logistic models for prolonged total LOS are presented in Table 3. Consistent with the findings of our primary analysis, perioperative complications were independently associated with the highest risk for prolonged total LOS: endometritis (aOR = 9.81), ileus (aOR = 9.28), wound complications (aOR = 5.0), postpartum RBC transfusion (aOR = 2.67), and hysterectomy during cesarean (aOR = 2.02). However, these point estimates were all lower than those observed for prolonged postpartum LOS. The PAF for endometritis for prolonged total LOS was 16.2% (95% CI = 15.3–17.1%). The PAFs for prolonged total LOS were lower for ileus 1.9% (95% CI = 1.6–2.2%) and wound complications 2.3% (95% CI = 1.9–2.7%).
Discussion
Among 57,812 women who underwent cesarean delivery in the MFMU network between 1999 and 2002, 14,954 women incurred a prolonged postpartum LOS. We identified several maternal, medical, and obstetric characteristics linked to prolonged postpartum LOS: African American race, BMI ≥ 40, diabetes, asthma, chronic hypertension, multiple pregnancy, ≥ 1 prior cesarean, and pregnancy-associated hypertensive disorders. In addition, specific perioperative morbidities (general anesthesia, uterine atony, transfusion, hysterectomy, endometritis, ileus, wound complications), and perinatal factors (preterm delivery, neonatal birth weight) were also independently associated with prolonged postpartum LOS. Of these, ileus, endometritis, and wound complications conferred the highest risk for prolonged postpartum LOS. These surgery-related complications also conferred the highest risk for a prolonged total LOS. Based on our findings, attention should be focused on developing new approaches for managing high-risk patients and improving surgical practices to decrease the risk of prolonged LOS after cesarean delivery.
In our cohort, patient, perioperative, and perinatal-related factors were associated with prolonged postpartum and prolonged total LOS. Although the etiologies for prolonged LOS could not be ascertained, many of the risk factors for prolonged LOS identified in our study have also been linked to obstetric morbidity. African American women have been reported to have the highest rates of morbidity compared with women of other races or ethncities.11,12 Furthermore, obese women are known to be at increased risk of intrapartum morbidity, prolonged hospital stay, and wound complications related to cesarean delivery.13,14 We found that women with indicators for severe obstetric hemorrhage (transfusion, hysterectomy) had at least a 1.8-fold increased odds of prolonged postpartum LOS. Our findings are in keeping with those from other population wide studies that have identified hemorrhage-related morbidities, notably transfusion and hysterectomy, as important indicators of obstetric morbidity.2,15 Women who had undergone ≥ 1 prior cesarean delivery were observed to be at an increased risk of prolonged postpartum LOS compared with women who had no prior cesareans.
Among the independent variables examined, patients who developed endometritis, ileus, or wound complications had the highest risk of prolonged postpartum and total LOS. The morbidity associated with endometritis may be underappreciated, especially as rates of postcesarean endometritis reported in other studies are high, ranging from 16.9% to 32%.16,17 While the Cesarean registry did not contain detailed data on antibiotic protocols or operative techniques, the high rate of endometritis among women with prolonged LOS deserves attention. Ileus, a potentially modifiable perioperative complication, had the highest odds for prolonged postpartum LOS. It is possible that early feeding after cesarean delivery may reduce the risk of ileus and secondarily prolonged postpartum LOS. In a recent meta-analysis, early oral intake after cesarean delivery was associated with the earlier return of gastrointestinal function and did not increase the occurrence of gastrointestinal complications.18 Though not all studies included in this meta-analysis reported LOS, one randomized controlled trial found early feeding to be associated with a significantly shorter hospital stay (4.8 vs. 6.7 days).19
Although postoperative LOS may be a useful outcome for analyzing obstetric morbidity, the Agency for Healthcare Research and Quality and the National Quality Forum have not identified LOS as an indicator of maternal quality of care.20,21 Renewed efforts are needed to improve the perioperative and postoperative care of low- and high-risk patients undergoing cesarean delivery to reduce the health care and cost burden of prolonged hospitalization. In nonobstetric surgical settings, multidisciplinary pathways have been adopted which have successfully reduced LOS after surgery.22–24
The major strength of this study is that the Cesarean registry comprises clinical data on more than 57,000 women who underwent cesarean delivery at the 19 U.S. obstetric centers. Due to the large sample size and quality of the clinical data available in the registry, we were able to investigate the influence of several candidate variables on prolonged LOS.
We acknowledge that our study has several limitations. Hospitals within the MFMU network were academic and university affiliated, therefore, our findings may not be generalizable to all hospital settings. However, the median total and postpartum LOS found in our cohort was 3 days, respectively. This finding is consistent with the mean LOS (3.5 days) for cesarean delivery at a national level (from the 2006 National Hospital Discharge Survey).25 We could not account for other unmeasured clinical factors that may have influenced postpartum LOS, such as intraoperative adhesions and severity of postoperative pain26,27 along with total hospital LOS (such as obstetric and fetal conditions that warrant early antenatal admission). In addition, other hospital-level or patient-level factors may have influenced LOS after cesarean delivery, such as institution-specific criteria for patient discharge, individual obstetrician’s years of experience, physician and nursing efficiencies of postpartum care, and patient preferences for the day of hospital discharge. These nuanced data were not available in the Cesarean registry. Further studies are needed to validate these findings and to elucidate etiologies for prolonged LOS after the cesarean delivery.
Based on our findings, preexisting obstetric disease and potentially modifiable perioperative complications such as endometritis, ileus, wound complications, and hemorrhage-related morbidities were identified as risk factors for prolonged LOS after cesarean delivery. These data highlight the need to optimize the preoperative and perioperative care of women undergoing cesarean delivery. By adopting strategies to improve the care of high-risk women undergoing cesarean delivery and decreasing rates of perioperative morbidity, the health care burden of prolonged LOS may be reduced.
Acknowledgments
Funding
This study was internally funded by the Department of Obstetrics and Gynecology and the Department of Anesthesia at Stanford University School of Medicine. A. J. B. is a recipient of an award from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (1K23HD070972).
We acknowledge the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), the Maternal-Fetal Medicine Units (MFMU) Network, and the Protocol Subcommittee for making this database available. The contents of this article represent the views of the authors and do not represent the views of the NICHD and MFMU Network or the National Institutes of Health.
Footnotes
Conflict of Interest
The authors report no conflict of interest.
Note
The article was presented in poster format at: 34th Annual Meeting of the Society for Maternal-Fetal Medicine; February, 2014; New Orleans, LA and 46th Annual Meeting of the Society for Obstetric Anesthesia and Perinatology, May, 2014; Toronto, Canada.
Contribution to Authorship
Y. B., D. L., Y. E. S., and A. J. B. assisted with conception of the study, study design, data analysis, and article writing. L. M. N. assisted with data analysis and article writing.
This study was given a waiver of exemption from the Stanford University Institutional Review Board approval as the Caesarean registry dataset contains deidentified data.
References
- 1.Hamilton BE, Martin JA, Ventura SJ. Births: preliminary data for 2012. Natl Vital Stat Rep. 2013;62(3):1–20. [PubMed] [Google Scholar]
- 2.Kuklina EV, Meikle SF, Jamieson DJ, et al. Severe obstetric morbidity in the United States: 1998–2005. Obstet Gynecol. 2009;113(2 Pt 1):293–299. doi: 10.1097/AOG.0b013e3181954e5b. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Dahlke JD, Mendez-Figueroa H, Rouse DJ, Berghella V, Baxter JK, Chauhan SP. Evidence-based surgery for cesarean delivery: an updated systematic review. Am J Obstet Gynecol. 2013;209(4):294–306. doi: 10.1016/j.ajog.2013.02.043. [DOI] [PubMed] [Google Scholar]
- 4.Caughey AB, Cahill AG, Guise JM, Rouse DJ American College of Obstetricians and Gynecologists (College); Society for Maternal-Fetal Medicine. Safe prevention of the primary cesarean delivery. Am J Obstet Gynecol. 2014;210(3):179–193. doi: 10.1016/j.ajog.2014.01.026. [DOI] [PubMed] [Google Scholar]
- 5.D’Alton ME, Bonanno CA, Berkowitz RL, et al. Putting the “M” back in maternal-fetal medicine. Am J Obstet Gynecol. 2013;208(6):442–448. doi: 10.1016/j.ajog.2012.11.041. [DOI] [PubMed] [Google Scholar]
- 6.Raleigh VS, Cooper J, Bremner SA, Scobie S. Patient safety indicators for England from hospital administrative data: case-control analysis and comparison with US data. BMJ. 2008;337:a1702. doi: 10.1136/bmj.a1702. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Morris MS, Deierhoi RJ, Richman JS, Altom LK, Hawn MT. The relationship between timing of surgical complications and hospital readmission. JAMA Surg. 2014;149(4):348–354. doi: 10.1001/jamasurg.2013.4064. [DOI] [PubMed] [Google Scholar]
- 8.Gruskay JA, Fu M, Basques B, et al. Factors Affecting Length of Stay and Complications Following Elective Anterior Cervical Discectomy and Fusion: A Study of 2164 Patients From The American College of Surgeons National Surgical Quality Improvement Project Database (ACS NSQIP) J Spinal Disord Tech. 2014 doi: 10.1097/BSD.0000000000000080. Epub ahead of print. [DOI] [PubMed] [Google Scholar]
- 9.Rouse DJ, Landon M, Leveno KJ, et al. National Institute of Child Health And Human Development, Maternal-Fetal Medicine Units Network. The Maternal-Fetal Medicine Units cesarean registry: chorioamnionitis at term and its duration-relationship to outcomes. Am J Obstet Gynecol. 2004;191(1):211–216. doi: 10.1016/j.ajog.2004.03.003. [DOI] [PubMed] [Google Scholar]
- 10.Greenland S, Drescher K. Maximum likelihood estimation of the attributable fraction from logistic models. Biometrics. 1993;49(3):865–872. [PubMed] [Google Scholar]
- 11.Creanga AA, Bateman BT, Kuklina EV, Callaghan WM. Racial and ethnic disparities in severe maternal morbidity: a multistate analysis, 2008–2010. Am J Obstet Gynecol. 2014;210(5):435.e1–435.e8. doi: 10.1016/j.ajog.2013.11.039. [DOI] [PubMed] [Google Scholar]
- 12.Mhyre JM, Bateman BT, Leffert LR. Influence of patient comorbidities on the risk of near-miss maternal morbidity or mortality. Anesthesiology. 2011;115(5):963–972. doi: 10.1097/ALN.0b013e318233042d. [DOI] [PubMed] [Google Scholar]
- 13.Scott-Pillai R, Spence D, Cardwell CR, Hunter A, Holmes VA. The impact of body mass index on maternal and neonatal outcomes: a retrospective study in a UK obstetric population, 2004–2011. BJOG. 2013;120(8):932–939. doi: 10.1111/1471-0528.12193. [DOI] [PubMed] [Google Scholar]
- 14.Denison FC, Norwood P, Bhattacharya S, et al. Association between maternal body mass index during pregnancy, short-term morbidity, and increased health service costs: a population-based study. BJOG. 2014;121(1):72–81. doi: 10.1111/1471-0528.12443. [DOI] [PubMed] [Google Scholar]
- 15.Callaghan WM, Creanga AA, Kuklina EV. Severe maternal morbidity among delivery and postpartum hospitalizations in the United States. Obstet Gynecol. 2012;120(5):1029–1036. doi: 10.1097/aog.0b013e31826d60c5. [DOI] [PubMed] [Google Scholar]
- 16.Andrews WW, Hauth JC, Cliver SP, Savage K, Goldenberg RL. Randomized clinical trial of extended spectrum antibiotic prophylaxis with coverage for Ureaplasma urealyticum to reduce post-cesarean delivery endometritis. Obstet Gynecol. 2003;101(6):1183–1189. doi: 10.1016/s0029-7844(03)00016-4. [DOI] [PubMed] [Google Scholar]
- 17.Atkinson MW, Owen J, Wren A, Hauth JC. The effect of manual removal of the placenta on post-cesarean endometritis. Obstet Gynecol. 1996;87(1):99–102. doi: 10.1016/0029-7844(95)00359-2. [DOI] [PubMed] [Google Scholar]
- 18.Hsu YY, Hung HY, Chang SC, Chang YJ. Early oral intake and gastrointestinal function after cesarean delivery: a systematic review and meta-analysis. Obstet Gynecol. 2013;121(6):1327–1334. doi: 10.1097/AOG.0b013e318293698c. [DOI] [PubMed] [Google Scholar]
- 19.Orji EO, Olabode TO, Kuti O, Ogunniyi SO. A randomised controlled trial of early initiation of oral feeding after cesarean section. J Matern Fetal Neonatal Med. 2009;22(1):65–71. doi: 10.1080/14767050802430826. [DOI] [PubMed] [Google Scholar]
- 20.Mehrabadi A, Hutcheon JA, Lee L, Kramer MS, Liston RM, Joseph KS. Epidemiological investigation of a temporal increase in atonic postpartum haemorrhage: a population-based retrospective cohort study. BJOG. 2013;120(7):853–862. doi: 10.1111/1471-0528.12149. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Roberts CL, Cameron CA, Bell JC, Algert CS, Morris JM. Measuring maternal morbidity in routinely collected health data: development and validation of a maternal morbidity outcome indicator. Med Care. 2008;46(8):786–794. doi: 10.1097/MLR.0b013e318178eae4. [DOI] [PubMed] [Google Scholar]
- 22.Yamaki S, Satoi S, Toyokawa H, et al. The clinical role of critical pathway implementation for pancreaticoduodenectomy in 179 patients. J Hepatobiliary Pancreat Sci. 2013;20(3):271–278. doi: 10.1007/s00534-012-0506-x. [DOI] [PubMed] [Google Scholar]
- 23.Pearson SD, Kleefield SF, Soukop JR, Cook EF, Lee TH. Critical pathways intervention to reduce length of hospital stay. Am J Med. 2001;110(3):175–180. doi: 10.1016/s0002-9343(00)00705-1. [DOI] [PubMed] [Google Scholar]
- 24.Lawrence JK, Keller DS, Samia H, et al. Discharge within 24 to 72 hours of colorectal surgery is associated with low readmission rates when using Enhanced Recovery Pathways. J Am Coll Surg. 2013;216(3):390–394. doi: 10.1016/j.jamcollsurg.2012.12.014. [DOI] [PubMed] [Google Scholar]
- 25.Oliphant SS, Jones KA, Wang L, Bunker CH, Lowder JL. Trends over time with commonly performed obstetric and gynecologic inpatient procedures. Obstet Gynecol. 2010;116(4):926–931. doi: 10.1097/AOG.0b013e3181f38599. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 26.Carvalho B, Coleman L, Saxena A, Fuller AJ, Riley ET. Analgesic requirements and postoperative recovery after scheduled compared to unplanned cesarean delivery: a retrospective chart review. Int J Obstet Anesth. 2010;19(1):10–15. doi: 10.1016/j.ijoa.2009.02.012. [DOI] [PubMed] [Google Scholar]
- 27.Lyell DJ. Adhesions and perioperative complications of repeat cesarean delivery. Am J Obstet Gynecol. 2011;205(6, Suppl):S11–S18. doi: 10.1016/j.ajog.2011.09.029. [DOI] [PubMed] [Google Scholar]