Objective: To compare the risk of neonatal morbidity and infant mortality between elective early-term deliveries and those expectantly managed and delivered at 39 weeks of gestation or greater.
Methods: We conducted a population-based retrospective cohort study of 675,302 singleton infants born alive at 37-44 weeks of gestation from 2005 to 2009 in more than 125 birthing facilities in Florida. Data were collected from a validated, longitudinally linked maternal and infant database. The study population was categorized into exposure groups based on the timing and reason for delivery initiation-four subtypes of deliveries at 37-38 weeks of gestation and a comparison group of expectantly managed infants delivered at 39-40 weeks of gestation. Primary outcomes included neonatal respiratory morbidity, sepsis, feeding difficulties, admission to the neonatal intensive care unit (NICU), and infant mortality.
Results: Neonatal outcome rates ranged from 6.0% for respiratory morbidities to 1.3% for both sepsis and feeding difficulties, and the infant mortality rate was 1.5 per 1,000 live births. When compared with infants expectantly managed and delivered at 39-40 weeks of gestation, those delivered after elective induction at 37-38 weeks of gestation did not have increased odds of neonatal respiratory morbidity, sepsis, or NICU admission but did experience slightly higher odds of feeding difficulty (odds ratio 1.18, 99% confidence interval 1.02-1.36). In contrast, infants delivered by elective cesarean at 37-38 weeks of gestation had 13-66% increased odds of adverse outcomes. Survival experiences were similar when comparing early inductions and early cesarean deliveries with the expectant management group.
Conclusion: The issues that surround the timing and reasons for delivery initiation are complicated and each pregnancy unique. This study cautions against a general avoidance of all elective early-term deliveries.