A study of gemeprost alone, dilapan or mifepristone in combination with gemeprost for the termination of second trimester pregnancy

Abstract

It is well established that abortion can be induced successfully in midtrimester of pregnancy by gemeprost vaginal pessaries. A randomised study was carried out to determine the efficacy of mifepristone and dilapan in combination with gemeprost for second trimester termination between 12-18 weeks' gestation. A contemporary group of women treated with gemeprost alone was used as a control group. A single course of 4 x 1 mg gemeprost pessaries was administered every six hours. If abortion had not occurred after 24 hours, a further course of 5 x 1 mg pessaries was administered every three hours over the next 24 hours. In the first twenty hours after administration of gemeprost, 95%, 85% and 72% of women aborted in the mifepristone, dilapan and the control group, respectively. The median induction-abortion interval in the mifepristone group (6.6h) was significantly shorter than the other two groups and fewer pessaries were required to induce abortion. The incidence of diarrhoea and vomiting was lower in the mifepristone than the other two study groups. This study demonstrated the efficacy of mifepristone in combination with gemeprost and this regimen is associated with fewer gastrointestinal side effects.

PIP: The results of a comparative study suggest that a combination of mifepristone and gemeprost is a safe, effective regimen for the termination of second-trimester pregnancy. 98 women who presented for second-trimester abortion at an Edinburgh family planning clinic were included in the study and randomly allocated to 1 of 3 groups: I--58 controls who were treated with gemeprost alone, II--20 women pretreated with gemeprost and dilapan, and III--20 patients pretreated with an oral dose of 200 mg of RU-486 and gemeprost. In all 3 groups, gemeprost pessaries were inserted every 6 hours and, if abortion had not occurred by 24 hours, every 3 hours over the next 24 hours. In the first 24 hours after gemeprost administration, 72% of controls, 85% of women in Group II, and 95% of those in Group III had aborted. The median induction-abortion interval was 6.6 hours in the gemeprost-RU-486 group. The lower dose of both these agents required to effect abortion meant there were fewer side effects (vomiting and diarrhea) in Group III. Although pretreatment with dilapan produced a median cervical dilatation of 9.5 mm, there was no significant difference in the induction-abortion interval between Groups I and II. This finding suggests that it is the increased sensitivity of the myometrium to prostaglandin after RU-486 administration that accelerated abortion in women in Group III rather than an effect on cervical dilatation. Additional research is needed to determine the optimal RU-486 and gemeprost dosages for midtrimester abortions.