An open study comparing two regimens of gemeprost for the termination of pregnancy in the second trimester.

Two regimens of the prostaglandin E1 analogue, gemeprost, were compared in an open trial for termination of pregnancy between 12 and 18 weeks. Fifty women received 5 x 1 mg of gemeprost every 3 h and in another 50 cases, 4 x 1 mg of gemeprost was administered every 6 h. Although the median abortion interval was slightly shorter in the 3-hourly group (15.9 h vs. 16.9 h; p = 0.5), the cumulative abortion rates at 24 h were similar (88% vs. 82%; p less than 0.5). In women who aborted within the first 24 h, significantly fewer pessaries (p less than 0.01) were required to induce abortion in the 6-h treatment group (median 3, range 1-4) than the 3-h group (median 5, 2-5). Parous women in both treatment groups required fewer pessaries to induce abortion than did nulliparous women (not significant; p = 0.5). Significantly (p less than 0.01) fewer pessaries were required to induce abortion in the 6-h gemeprost group. The were no significant differences between the groups regarding incidences of diarrhea, vomiting, or the request for analgesia. These results suggest that in many women the number of pessaries used to induce mid-trimester abortion could be reduced by lengthening the interval between insertion of pessaries within the first 24 h, without loss of clinical efficacy.