(1012) Induction versus expectant management in multiparous low-risk women: Single institution impact of the ARRIVE Trial

The ARRIVE trial found that elective induction of labor (eIOL) at 39 weeks in nulliparous persons compared to expectant management was associated with a lower rate of cesarean delivery (CD). The benefit of eIOL in a multiparous population is less certain. Our goal was to evaluate the performance of low-risk multiparous women undergoing eIOL at 39 weeks.

Study Design:

Retrospective cohort study of all multiparous pregnant persons admitted for delivery ≥ 39w0d at a single academic community institution between 3/1/20-3/1/22, when we started offering eIOL. Those with singleton low risk pregnancies, without any clinical indication for delivery prior to 40w5d, were included. Maternal and neonatal outcomes of persons undergoing eIOL between 39w0d-39w4d were compared to women expectantly managed. The primary outcome was rate of CD. Secondary outcomes included select maternal outcomes and composite neonatal outcome (neonatal death and/or serious morbidity).

Results:

1141 multiparous persons with low-risk singleton gestations were identified, with 297 (26%) undergoing eIOL and 844 (74%) expectantly managed. Those undergoing eIOL delivered earlier (39.2 vs 40.0, p< 0.001) and were more likely to be obese (34.4 vs 23.7%, p< 0.001) and have diet controlled gestational diabetes (10.1 vs 6.4%, p=0.04) (Table). The CD rate was similar between the eIOL and expectant management groups (2.7% vs 2.0%, p=0.49). Elective IOL was associated with longer maternal but similar newborn lengths of stay compared to expectant management. The composite neonatal outcome occurred in significantly fewer neonates in the eIOL group compared to the expectant management group (4.0% vs 8.3%, p=0.02), primarily due to decreased need for respiratory support in the eIOL group (1.7% vs. 4.5%, p=0.03).

Conclusion: In our cohort of low-risk multiparous pregnant persons, eIOL at 39w0d-39w4d did not decrease CD rate but did decrease composite neonatal risk. Like the findings of ARRIVE trial in a nulliparous population, our findings suggest that eIOL at term for multiparous patients is safe and may have benefit.