Medical abortion at 57 to 63 days’ gestation with a lower dose of mifepristone and gemeprost

Objective. To compare the abortifacient efficacy and side‐effects of 200 mg and 600 mg of mifepristone, followed by gemeprost 1 mg vaginally, at 57 to 63 days’ gestation. Design. Double‐blind, randomized controlled trial. Setting. Ten international centers. Subjects. Eight hundred and ninety‐six healthy women requesting medical abortion. Interventions. Participants were randomly assigned to receive a single oral dose of mifepristone of either 200 mg or 600 mg followed in 48 h by gemeprost 1 mg vaginally. The allocation sequence was concealed by using a central pharmacy, and double masking was maintained throughout the study. Main outcome measures. Complete abortion rate was the principal outcome measure. We also evaluated the incidence of side‐effects and time to abort. Results. The complete abortion rate with the lower dose of mifepristone was similar to that with the higher dose (92.4% vs . 91.7%). The relative risk of failure to achieve a complete abortion with the 200 mg dose compared to 600 mg dose was 0.9 (95% CI 0.6–1.4). The timing of the abortion and the incidence of side‐effects were comparable in both groups, with the exception of reported nausea at one‐week follow‐up which was reported more frequently by women in the higher‐dose group. Conclusions. The 200 mg dose of mifepristone is equally as effective as the 600 mg dose in the antiprogestogen‐prostaglandin regimen for pregnancy termination. With vaginal gemeprost, the abortifacient efficacy of the regimen remains high at 57–63 days’ gestation.