A comparison of 600 and 200 mg mifepristone prior to second trimester abortion with the prostaglandin misoprostol

Objective To compare the use of 600 and 200 mg mifepristone prior to second termination of pregnancy with the prostaglandin misoprostol. Design A randomised study. Setting A Scottish teaching hospital. Participants Seventy women undergoing legal induced abortion between 13 and 20 weeks of gestation. Intervention Administration of either 600 or 200 mg mifepristone 36 to 48 hours prior to prostaglandin. Main outcome measure Induction-abortion interval. Results The geometric mean induction abortion interval was 6.9 (95% CI 5.8-8.4) h and 6.9 (95% CI 5.8-8.2) h in the 600 and 200 mg groups, respectively (no significant difference). The median dose of misoprostol was 1600 mu g (three doses) in each group. Analgesic requirements and prostaglandin-related side effects were similar between groups. Overall, 1.4% of women required surgical evacuation of the uterus as a result of retained placenta. Conclusions The dose of mifepristone used in second trimester abortion can be reduced from 600 to 200 mg.