Randomized trial of oral versus vaginal misoprostol 2 days after mifepristone 200 mg for abortion up to 63 days of pregnancy.

Abstract

This prospective, open-label, randomized trial of healthy adult women up to 9 weeks pregnant compared mifepristone 200 mg followed 2 days later with misoprostol 400 microg orally versus misoprostol 800 microg vaginally. The study was interrupted after the oral misoprostol group experienced a higher than expected failure rate. This treatment was discontinued and another substituted consisting of oral misoprostol 800 microg divided into two doses two hours apart. Women returned for a follow-up visit from Day 4 to 8. All women with a continuing pregnancy received a repeat dose of misoprostol vaginally and returned before Day 15. The primary outcome measure was a complete medical abortion without surgical intervention at the first visit. Of the 1045 women enrolled, 1011 had complete data: Group 1 (220) used oral misoprostol 400 microg, Group 2 (269) used oral misoprostol 800 microg, and Group 3 (522) used vaginal misoprostol 800 microg. At first follow-up visit, the primary outcome, that is, a complete abortion, was 84% for Group 1, 92% for Group 2, and 96% for Group 3, p < 0.001. After a second dose of vaginal misoprostol in women with on-going pregnancies at their first follow-up visit, the complete abortion rates were 91%, 95%, and 98%, respectively, p < 0.001. There were minimal differences in side effects, onset of bleeding and overall acceptability in the three groups. Mifepristone 200 mg followed by vaginal misoprostol 2 days later was more effective at inducing an abortion up to 9 weeks of pregnancy than the same dose of mifepristone followed by oral misoprostol.