Objective: To compare maternal and neonatal outcomes in women who underwent induction of labor or planned cesarean delivery in indicated preterm births before 34 weeks of gestation.
Methods: We conducted a retrospective cohort study of all indicated singleton preterm births (23-34 weeks of gestation) in a tertiary center from 2011 to 2014. The primary maternal outcome was a composite of early postpartum hemorrhage, blood transfusion, operative complications, postpartum complications, and clinical chorioamnionitis. The primary neonatal outcome was a composite of neonatal death, cardiopulmonary resuscitation in the delivery room, grade 3 or 4 intraventricular hemorrhage, necrotizing enterocolitis, culture-proven sepsis, birth trauma, arterial cord gas pH less than 7 or base excess less than -12, and 5-minute Apgar score 3 or less. Outcomes were compared by intended mode of delivery (induction of labor compared with cesarean) and adjusted for confounders. In secondary analyses, maternal and neonatal outcomes based on the intended mode of delivery were stratified by gestational age (23-27 6/7, 28-31 6/7, and 32-33 6/7 weeks of gestation).
Results: Of 629 patients with indicated early preterm births during the study period, 331 (53%) underwent induction of labor, of whom 208 (63%) delivered vaginally. Induction of labor was not associated with an increased risk of the primary maternal (16.3% compared with 19.5%, adjusted odds ratio [OR] 0.8, 95% CI 0.5-1.3) or neonatal composite outcome (14.5% compared with 35.9%, adjusted OR 0.7, 95% CI 0.4-1.1). Analyses stratified by gestational age were consistent with the overall analysis.
Conclusion: Maternal and neonatal outcomes do not differ based on the intended mode of delivery. Induction of labor should be considered when early preterm birth is indicated.