Mifepristone 100 mg in abortion regimens

Abstract

Objective: To examine the clinical efficacy of mifepristone 100 mg followed 2 days later by misoprostol 400 microg orally or 800 microg vaginally in women at up to 49 days' gestation.

Methods: Eighty participants received mifepristone 100 mg and then were randomized to misoprostol, administered 48 hours later, at a dose of 400 microg orally (group 1) or 800 microg vaginally (group 2). Women returned for follow-up evaluations 24 +/- 1 hour after using the misoprostol and then 2-3 weeks later. If abortion still had not occurred and the pregnancy was nonviable, the subject returned again after an additional 3 weeks.

Results: Twenty-four hours after receiving misoprostol, 34 (85%; 95% confidence interval [CI] 71%, 94%) of the 40 women in group 1 and 38 (95%; 95% CI 85%, 99%) of the 40 women in group 2 had complete abortions. Overall, complete abortion without surgical intervention occurred in 34 women in group 1 (85%; 95% CI 71%, 94%) and 40 women in group 2 (100%; 95% CI 91%, 100%; P =.03). Four women in group 1 required suction aspiration for continuing pregnancy at the second follow-up, compared with none in group 2 (P =.12). Side effects occurred with similar frequency in both treatment groups.

Conclusion: Low-dose mifepristone (100 mg) combined with vaginal misoprostol 800 microg may be an effective alternative to regimens using 200 or 600 mg of mifepristone with misoprostol.