Induction of abortion in the second trimester by a combination of misoprostol and mifepristone: a randomized comparison between two misoprostol regimens

Abstract

The combination of mifepristone (RU486) and prostaglandin is effective in the induction of abortion in the second trimester. The optimal regimen is still under development, but is likely to be characterized by a short induction-to-abortion interval, low incidence of side-effects and high acceptability. We have investigated further whether misoprostol, a synthetic prostaglandin E1 analogue, can reliably induce second trimester abortion in 70 women pre-treated with mifepristone, and whether different routes of administration affect the induction-to-abortion interval. Abortion was achieved in 97% [95% confidence interval (CI) 90-100%] of cases without resort to other prostaglandin agents. The mean induction abortion time for the studied population was 6.4 h (95% CI 5.6-7.0 h). No significant difference was found between two different routes of administration, namely vaginal versus a combination of vaginal and oral. Misoprostol has a number of advantages over other prostaglandin preparations. We recommend that, following pre-treatment with mifepristone, misoprostol is used as the prostaglandin of choice to induce abortion in the second trimester.