The quest to reduce neonatal jaundice readmissions is built on research examining risk factors, two of which are postpartum length of stay (1) and late preterm (34 to 36 completed weeks’ gestation) delivery (2). Further research has revealed that mortality (3) and neonatal morbidity (4) are higher in early-term (37 to 38 completed weeks’ gestation) compared with full-term (39 to 41 completed weeks’ gestation) infants, although few studies have been published. The present report describes the relationship among gestational age, length of stay at birth and readmission for jaundice, for the purpose of informing discharge planning and health policy.
METHODS
A retrospective cohort of all liveborn infants within Manitoba of 34 to 41 completed weeks’ gestation during two fiscal years (2004/2005 to 2005/2006) was obtained from the data repository at the Manitoba Centre for Health Policy following appropriate ethics and data custodian approvals. This data system contains multiple anonymized administrative datasets linked by scrambled personal identification numbers, and has previously been validated. Approximately two-thirds of all deliveries in Manitoba occur in Winnipeg, with the remainder occurring throughout the province. Public health nurse follow-up is offered to all families one to three days after discharge.
The primary outcome was neonatal readmission (within 28 days of birth) for which the ‘most responsible diagnosis’ was jaundice (International Classification of Diseases, 10th Revision codes R17, P55, 57–59). Two independent variables – gestational age at birth (in completed weeks) as a categorical variable, and short postpartum stay (≤2 calendar days) as a binomial variable – were studied in a multivariate logistic regression model. Gestational age was obtained from the maternal delivery record and based on menstrual dates or second-trimester ultrasound. The model controlled for maternal diabetes, parity, maternal age, need for ventilation at birth, sex, birth morbidity, neonatal intensive care unit stay at birth, congenital anomalies, rural residence, breastfeeding at birth, area level income and jaundice at birth, as described previously (5). Analyses were performed using SAS version 9.3 (SAS Institute, USA).
RESULTS
The final cohort consisted of 25,237 infants after exclusions (missing data, n=86; moving before first birthday, n=436; birth stays >28 days, n=75) and is described in Table 1. The overall unadjusted readmission rate was 0.7%; no 34-week infants were readmitted. The rates increased with each week of gestation until 37 weeks (Table 2). Short stay increased as gestational age increased (Table 1). Initially, gestational age was entered as an interaction with short stay in the regression model, but because this interaction was not significant (P=0.6), each was entered independently into the final model. In this adjusted model, infants born at 35 through 38 weeks’ gestation had significantly higher rates of readmission when compared with infants at 40 weeks’ gestation (Table 3). Analyses comparing each week to the next found that the adjusted odds were not significantly different between 35 and 36 weeks’ gestation (P=0.39) or between 36 and 37 weeks’ gestation (P=0.91); 37 weeks’ gestation was significantly higher than 38 weeks’ gestation (P=0.002). In the adjusted model, short stay increased the odds of readmission (OR 2.4 [95% CI 1.6 to 3.6]).
TABLE 1.
Description of the cohort according to gestational age at birth and percentage with each characteristic
| Gestational age, weeks | Short stay* | Rural† | NICU admission | Primiparous | Male sex | Any breastfeeding‡ | Delivery by Caesarean section | Maternal diabetes§ |
|---|---|---|---|---|---|---|---|---|
| 34 | 7.8 | 34.2 | 87.9 | 43.6 | 58.0 | 69.3 | 37.0 | 7.8 |
| 35 | 12.1 | 41.9 | 59.6 | 39.5 | 55.8 | 70.2 | 32.7 | 12.1 |
| 36 | 28.5 | 41.7 | 33.2 | 36.9 | 54.2 | 74.3 | 28.7 | 16.9 |
| 37 | 56.9 | 39.7 | 15.1 | 35.6 | 51.8 | 79.2 | 24.9 | 10.1 |
| 38 | 61.4 | 43.3 | 8.2 | 32.5 | 53.0 | 80.6 | 30.0 | 8.4 |
| 39 | 71.1 | 43.0 | 5.0 | 35.1 | 49.6 | 81.4 | 21.2 | 3.8 |
| 40 | 70.6 | 47.8 | 4.5 | 39.4 | 50.1 | 83.2 | 13.9 | 2.4 |
| 41 | 74.9 | 44.3 | 5.3 | 46.8 | 51.9 | 85.3 | 17.2 | 0.8 |
| Total | 66.5 | 44.2 | 8.8 | 38.1 | 51.2 | 81.7 | 20.8 | 4.7 |
≤2 calendar days;
Includes maternal residence in Winnipeg and Brandon, Manitoba;
Any breastfeeding during birth stay;
Includes types 1, 2 and gestational diabetes. NICU Neonatal intensive care unit (level 2/3)
TABLE 2.
Infants readmitted for jaundice in the first 28 days of life according to gestational age at birth in completed weeks
| Gestational age, weeks | Total n | Readmitted, n (%) |
|---|---|---|
| 34 | 257 | 0 (0) |
| 35 | 446 | 6 (1.3) |
| 36 | 792 | 16 (2.0) |
| 37 | 1774 | 37 (2.1) |
| 38 | 4179 | 43 (1.0) |
| 39 | 6521 | 27 (0.4) |
| 40 | 7215 | 32 (0.4) |
| 41 | 4053 | 12 (0.3) |
| Total | 25,237 | 173 (0.7) |
TABLE 3.
Adjusted* odds of readmission for jaundice within the first 28 days of life (n=172)
| Variable | OR (95% CI) |
|---|---|
| Short stay† | 2.4 (1.6–3.6) |
| Gestational age, weeks | |
| 35 | 3.2 (1.3–8.4) |
| 36 | 4.8 (2.5–9.2) |
| 37 | 5.0 (3.1–8.2) |
| 38 | 2.4 (1.5–3.9) |
| 39 | 1.0 (0.6–1.7) |
| 40 | Reference |
| 41 | 0.7 (0.3–1.3) |
Adjusted for maternal diabetes, parity, maternal age group, need for ventilation at birth, male sex, birth morbidity, neonatal intensive care unit stay at birth, congenital anomaly, rural residence, breastfeeding at birth and jaundice at birth;
≤2 calendar days
DISCUSSION
The present study examined the association of two key clinical variables – gestational age at birth and short postpartum stays – with risk for jaundice readmission. The results reveal that infants born at 37 weeks’ gestation remain at the same risk for significant jaundice as late preterm infants, and infants born at 38 weeks’ gestation remain at higher risk than full-term infants. Research examining early-term infants after birth discharge is sparse; however, our findings are supported by a recent large study demonstrating higher risks of any readmission for early-term compared with full-term infants (6), with feeding issues and jaundice being the most common reasons.
Our second important finding was that while a birth stay of ≤2 calendar days increased the risk of readmission, the magnitude of that risk was the same regardless of gestational age. This differs from findings in the study above (6), which showed statistical differences for preterm and full-term infants, but not early-term infants; however, stay was measured in hours, and the difference was approximately 1 h, which is of uncertain clinical significance.
To decrease the risks associated with neonatal jaundice, discharge and follow-up guidelines should be individualized for each infant and not mandated by gestational age at birth. Length of birth stay should be decided by considering the impact of gestational age until 38 weeks. Practitioners must identify readiness for discharge by ensuring that infants have demonstrated appropriate feeding skills, do not experience excessive weight loss and have good supports in the community with appropriate follow-up.
Acknowledgments
The authors thank the Manitoba Centre for Health Policy for use of data contained in the Population Health Research Data Repository under project #2008-021 (HIPC#2008/2009-29). The results and conclusions are those of the authors and no official endorsement by the Manitoba Centre for Health Policy, Manitoba Health or other data providers is intended or should be inferred. Data used in this study are from the Population Health Research Data Repository housed at the Manitoba Centre for Health Policy, University of Manitoba, and were derived from data provided by Manitoba Health and Manitoba Vital Statistics, Canada Census and Manitoba Entrepreneurship, Training and Trade.
Footnotes
DISCLOSURES: This work originated at the University of Manitoba, Department of Community Health Sciences, Manitoba Centre for Health Policy (Winnipeg, Manitoba). The study was approved by the Health Research Ethics Board, University of Manitoba, and the Health Information Privacy Committee of Manitoba.
REFERENCES
- 1.Truman C, Johnson D, Jin Y. Early discharge of Alberta mothers post-delivery and the relationship newborn readmissions. Can J Public Health. 2000;93:276–80. doi: 10.1007/BF03405016. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Burgos AE, Schmitt SK, Stevenson DK, Phibbs CS. Readmission for neonatal jaundice in California, 1991–2000: Trends and implications. Pediatrics. 2008;121:e864–9. doi: 10.1542/peds.2007-1214. [DOI] [PubMed] [Google Scholar]
- 3.Reddy UM, Bettegowda VR, Dias T, Yamada-Kushnir T, Ko C-W, Willinger M. Term pregnancy: A period of heterogeneous risk for infant mortality. Obstet Gynecol. 2011;117:1279–87. doi: 10.1097/AOG.0b013e3182179e28. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Tita AT, Landon MB, Spong CY, et al. Timing of elective repeat Cesarean delivery at term and neonatal outcomes. N Engl J Med. 2009;360:111–20. doi: 10.1056/NEJMoa0803267. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Ruth CA, Roos N, Hildes-Ripstein E, Brownell M. The influence of gestational age and socioeconomic status on neonatal outcomes in late preterm and early term gestation: A population based study. BMC Pregnancy Childbirth. 2012;12:62. doi: 10.1186/1471-2393-12-62. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Young PC, Korgenski K, Buchi KF. Early readmission of newborns in a large health care system. Pediatrics. 2013;131:e1538–44. doi: 10.1542/peds.2012-2634. [DOI] [PubMed] [Google Scholar]