(557) Keys to A Successful Induction in Patients with BMI > 40

The objective of this study was to determine factors associated with a successful induction of labor in patients with body mass index (BMI) > 40 kg/m².


Study Design:

This was a retrospective cohort study of 374 patients with BMI > 40 kg/m² who underwent induction of labor at a single academic institution from 2011-2021.


Results:

Induction of labor resulted in a vaginal delivery for 60% (255/374) of the patients. Those having a vaginal delivery had lower BMI at both their initial visit and at delivery, higher parity, rupture of membranes at an advanced cervical dilation, and a shorter length of induction. In contrast, women who had cesarean deliveries were more likely to have preeclampsia severe features, develop chorioamnionitis, use more doses of misoprostol, and reach higher doses of oxytocin. When comparing obesity classes [defined as Class III (BMI 40.0-49.9), Class IV (BMI 50-59.9) and Class V (BMI >60)], those with a lower BMI class had higher parity and shorter length of induction. In contrast, those with a higher BMI class were more likely to have a diagnosis of chronic hypertension and require higher doses of oxytocin.


Conclusion:

Patients with a lower BMI were more likely to deliver vaginally after an induction of labor. Specifically, higher parity, rupture of membranes at an advanced cervical dilation, and a shorter length of induction were associated with the success of a vaginal delivery in these patients. Comorbidities such as hypertensive disorders of pregnancy may affect the success of an induction in those with higher BMIs.