Buccal Versus Vaginal Misoprostol Combined with a Foley Catheter Among Individuals with Obesity Undergoing Induction

Background: 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. Objective: Our objective was to evaluate the difference in time to delivery of buccal compared to vaginal misoprostol in combination with a Foley catheter (FC) for labor induction (IOL) in the obese population. Study Design: This was a secondary analysis of a randomized controlled trial comparing identical dosages (25μg) 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 ≤2cm were included. Body mass index (BMI, kg/m2) was stratified. The primary outcome was time to delivery. Results: 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: 21.3hrs vs. buccal misoptostol–FC: 25.2hrs, 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 [HR] 1.2, 95% confidence interval [CI] 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. Therefore, vaginal misoprostol should be the preferred route of drug administration for term IOL in this population