Elective Term Induction Outcomes by Gestational Age in the Post-ARRIVE Era [ID 1612]

INTRODUCTION: Cesarean delivery rates in the United States remain historically high, with nearly 1 in 3 births occurring via cesarean. Since the ARRIVE trial, and subsequent changes in recommendations, there has been a 2.8- to 3-fold increase in elective inductions. This study aimed to evaluate rates of cesarean delivery, adverse neonatal outcomes, and adverse maternal outcomes associated with elective induction of labor (eIOL) at different gestational ages compared to expectant management. METHODS: This is a retrospective cohort study using data from the Obstetrics Initiative (OBI) on nulliparous, singleton, cephalic deliveries in Michigan from January 2022 to December 2023. We compared outcomes between women ages 18–45 who underwent eIOL versus expectant management at gestational ages of 39, 40, 41, and 42 weeks (N=4,711, 3,777, 1,748, 38, respectively; total N=10,274). Multivariate logistic regression models were used to assess differences in unplanned cesarean rates, composite adverse neonatal outcomes, and composite adverse maternal outcomes. RESULTS: In our analysis, eIOL at 39 weeks was associated with increased odds of cesarean delivery compared to expectant management (odds ratio 1.253; 95% CI, 1.011–1.553; P =.040). No significant differences were observed for deliveries at 40, 41, or 42 weeks ( P =.859, .262, .878, respectively). CONCLUSIONS/IMPLICATIONS: Elective IOL at 39 weeks is associated with a modestly increased likelihood of unplanned cesarean compared to expectant management. This association diminishes at later gestational ages. These findings suggest that timing of eIOL plays a critical role in outcomes, warranting further investigation into recommendations for induction practices.