Skip to main content
SMFM 2026 Pregnancy Meeting Main banner
Icon Legend
This session is not in your schedule.
This session is in your schedule. Click again to remove it.
Presentation Icons
Additional registration fee required
Additional registration fee required
Faculty have requested this content not be shared outside of the session
Faculty have requested this content not be shared outside of the session
CME Credit Offered
CME Credit Offered
Abstract Award
Abstract Award
Recording available 2/16-5/2
Recording available 2/16-5/2
AIUM Credit
AIUM Credit
Foundation Awardee
Foundation Awardee
Poster Icons
Abstract Award
Abstract Award
Foundation Awardee
Foundation Awardee

Poster Session 4

Category: Labor

Poster Session 4

(1022) Outcomes of non-medically indicated induction of labor at 39 weeks among births complicated by obesity

Thursday, February 12, 2026
3:30 PM - 5:00 PM  
Objective:
Given the recent increase in non-medically indicated induction of labor (IOL) following publication of the ARRIVE trial, it is important to assess perinatal outcomes for maternal factors that influence labor physiology and outcomes, such as obesity. We sought to assess perinatal outcomes of births complicated by obesity managed with IOL compared with expectant management (EM).

Study Design:
This was a retrospective cohort study of singleton, non-anomalous nulliparous births between 39-42 weeks in California between 2018-2020. We included births complicated by a pre-pregnancy body mass index of 30 kg/m2 or greater. Medical indications for IOL and planned cesarean deliveries were excluded. We examined maternal and neonatal outcomes using bivariate and multivariable analyses with a p value of 0.05.

Results:
There were 23,945 births included in this analysis, of which 4,346 (18%) were managed with IOL at 39 weeks. IOL was associated with lower risk for cesarean delivery (aIRR 0.94, 95% CI 0.89-0.98), large for gestational age (aIRR 0.87, 95% CI 0.79-0.95) and macrosomia (aIRR 0.62, 95% CI 0.57-0.69). There was a higher risk of operative vaginal delivery (aIRR 1.18, 95% CI 1.08-1.30).

Conclusion:
Among nulliparous births complicated by obesity, non-medically indicated IOL at 39 weeks is associated with lower cesarean deliveries, fewer neonates that are large for gestational age or macrosomic, and increased operative vaginal deliveries.