A randomised study of two doses of gemeprost in combination with mifepristone for induction of abortion in the second trimester of pregnancy.

Two regimens of the prostaglandin E1 analogue, gemeprost, in combination with mifepristone were compared in a randomised trial for termination of pregnancy between 12-19 weeks. Thirty-six hours after treatment with 200 mg mifepristone, women were allocated at random to receive either 4 x 1 mg (Group I) or 4 x 0.5 mg (Group II) gemeprost by vaginal pessary every 6 hours (n = 50 in each group). If abortion had not occurred after 24 h, 5 x 1 mg of gemeprost was administered every 3 h to both groups of women. Although the median abortion interval was slightly shorter in the 1 mg group (7.8 h vs. 8.4 h, p = 0.5), the cumulative abortion rates at 24 h were similar (98% vs. 96%). Women in Group I required significantly more gemeprost to induce abortion than Group II (p < 0.0001). Parous women in both groups required significantly less of the prostaglandin to induce abortion. In Group II, the median abortion interval was significantly longer in primigravidae than multigravidae (9.5 h vs. 6.1 h; p < 0.02). There were no significant differences between the groups in the incidence of vomiting, diarrhoea or the request for analgesia. The results suggest that in parous women, the dose of gemeprost can be reduced to 0.5 mg every 6 h within the first 24 h without loss of clinical efficacy.