Buccal versus Vaginal Misoprostol Combined with a Foley Catheter among Individuals with Obesity Undergoing Induction

Abstract

Objective: Combining pharmacologic agents with mechanical ripening achieves the shortest labor duration, yet there is no clear evidence on route of drug administration in obese individuals. The use of buccal misoprostol has shown greater patient acceptance but remains understudied. Our objective was to evaluate the difference in time to delivery of buccal compared with vaginal misoprostol in combination with a Foley catheter (FC) for induction of labor (IOL) in the obese population.

Study design: This was a secondary analysis of a randomized controlled trial comparing identical dosages (25 μg) of buccal and vaginal misoprostol in combination with a FC. The parent trial was an institutional review board-approved, randomized clinical trial conducted from June 2019 through January 2020. Labor management was standardized among participants. Women undergoing IOL at ≥37 weeks with a singleton gestation and cervical dilation ≤2 cm were included. Body mass index (BMI, kg/m²) was stratified. The primary outcome was time to delivery.

Results: A total of 215 participants were included. Demographic characteristics were similar between the three groups. Vaginal drug administration achieved a faster median time to delivery than the buccal route among patients with a body mass index greater than or equal to 30 kg/m² (vaginal misoprostol-FC: 21.3 hours vs. buccal misoprostol-FC: 25.2 hours, p = 0.006). There was no difference in the cesarean delivery rate between the two groups. Furthermore, patients with a BMI greater than or equal to 30 kg/m² receiving vaginal misoprostol delivered 1.2 times faster than women who received buccal misoprostol after censoring for cesarean delivery and adjusting for parity (hazard ratio: 1.2, 95% confidence interval: 1.1-1.7). There were no significant differences in maternal and neonatal outcomes.

Conclusion: We found that vaginal misoprostol was superior to buccal misoprostol when combined with a FC among individuals with a BMI greater than or equal to 30 kg/m². Vaginal misoprostol should be the preferred route of drug administration for term IOL in this population.

Key points: · Vaginal misoprostol was superior to buccal route among patients with obesity.. · There was no difference in the cesarean delivery rate between the two groups.. · Vaginal misoprostol should be the preferred route of administration among patients with obesity..