Objective: To examine the association between route of delivery and neonatal outcomes in a large, diverse cohort of preterm, appropriate-for-gestational-age neonates.
Methods: This is a retrospective cohort study examining New York City birth data for 1995-2003 linked to hospital discharge data. Data were limited to singleton, live-born, cephalic neonates delivered between 24 and 34 weeks of gestation. Exclusion criteria included congenital anomalies, forceps or vacuum assistance, birth weight missing, less than 500 g, or not appropriate for gestational age. Any neonatal diagnosis of intraventricular hemorrhage, seizure, sepsis, subdural hemorrhage, respiratory distress, 5-minute Apgar score less than 7, or neonatal death was considered significant. Associations between method of delivery and neonatal morbidities were estimated using logistic regression.
Results: Of 20,231 neonates meeting study criteria, 69.3% were delivered vaginally and 30.7% were delivered by cesarean. After controlling for maternal age, ethnicity, education, primary payer, prepregnancy weight, gestational age, diabetes, and hypertension, cesarean delivery compared with vaginal delivery was associated with increased odds of respiratory distress (39.2% compared with 25.6%, adjusted odds ratio [OR] 1.74, 95% confidence interval [CI] 1.61-1.89) and 5-minute Apgar score less than 7 (10.7% compared with 5.8%, adjusted OR 2.04, 95% CI 1.77-2.35).
Conclusion: In this preterm cohort, cesarean delivery was not protective against poor outcomes and in fact was associated with increased risk of respiratory distress and low Apgar score compared with vaginal delivery.