A randomized controlled trial evaluating same-day mifepristone and misoprostol compared to misoprostol alone for cervical preparation prior to second-trimester surgical abortion.

Objective: We evaluated initial cervical dilation with the addition of oral mifepristone to vaginal misoprostol as cervical preparation for same-daysecond-trimester dilation and evacuation (D&E).

Study Design: Women desiring abortion between gestational ages 14weeks 0days and 19weeks 6days were randomized to 200-mg mifepristone or identical placebo immediately followed by 400-mcg misoprostol vaginally 4-6h prior to D&E. Primary outcome was cervical dilation assessed by largest Hegar dilator passed without resistance. Secondary outcomes included total procedure time and participant and provider perceptions. We had 90% power to detect a 2-mm change in initial cervical dilation with a mean of 10mm (SD=3.0mm), requiring 48 participants in each arm.

Results: Of 100 women enrolled, 96 were randomized and completed the study. Age, race, gestational age (mean 17.4weeks, SD=1.3) and parity did not significantly differ. Mean initial Hegar dilation measurements were 11.7 and 10.9mm in the mifepristone and placebo groups, respectively, with difference of 0.8 [95% CI=-0.4, 2.0mm]. We found total procedure times of 11.8 and 13.0min, respectively (difference of 1.2min [95% CI=-2.4, 4.8min]. Participant and provider perceptions did not differ. All 96 procedures were completed without hemorrhage, cervical laceration or other observed complications.

Conclusion: The addition of mifepristone to vaginal misoprostol did not provide a significant increase in cervical dilation compared to misoprostol alone as cervical preparation 4-6h prior to D&E at 14weeks through 19weeks 6days.

Implications: Adding mifepristone for a short interval (4-6h) did not improve cervical preparation with misoprostol prior to D&E at 14-19weeks. Future studies should evaluate alternative timing intervals of medications for this purpose.