Objective: To determine whether the risk of cesarean section following uncomplicated pregnancies has been reduced by current obstetric practices by comparing the neonatal risk of vaginal deliveries with the risk incurred following abdominal delivery in otherwise uncomplicated pregnancies.
Design: Observational, cohort study. A subpopulation of 11,702 women without complications of pregnancy was identified from a perinatal database, classified by subsequent mode of delivery, and compared for neonatal morbidity. This analysis was repeated after the cesarean section group was further narrowed to include only "repeated elective" deliveries.
Setting: Low-risk inborn setting. Tertiary care (level III nursery) referral center and a community (level II nursery) hospital.
Intervention: Cesarean section performed electively, for cephalopelvic disproportion, or for failure to progress.
Outcome variables: Chosen prior to data analysis: neonatal mortality and morbidity.
Results: Groups differed with regard to ethnicity and sex. Infants who were delivered by cesarean section were more likely to have 1-minute Apgar scores less than 4, require intermediate or intensive nursery care at admission (6.3% vs 1.3% [P < .001]), and require greater respiratory support (mechanical ventilation, 1.6% vs 0.3%; oxygen therapy, 4.9% vs 1.4%; or room air, 93.5% vs 98.4% [P < .001]) than infants who were delivered vaginally. Similar results were found when patients who were delivered vaginally and by repeated elective cesarean section were compared.
Conclusion: Although reports have recently emerged suggesting otherwise, abdominal delivery following an uncomplicated pregnancy remains a risk factor for adverse neonatal outcome despite current obstetric practices.