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

Objective: To compare the effectiveness of gemeprost and misoprostol as prostaglandins used in combination with mifepristone for induction of mid-trimester termination.

Design: Randomised trial.

Setting: Scottish teaching hospital.

Sample: One hundred women undergoing abortion between 12 and 20 weeks.

Methods: Each woman received 200 mg mifepristone and 36-48 hours later either 1 mg gemeprost vaginal pessary every 6 hours for 18 hours or 4 x 200 microg misoprostol tablets vaginally followed by 2 x 200 microg misoprostol tablets orally every 3 hours for 12 hours. Success was defined as the percentage of women aborted within 24 hours of the first administration of prostaglandin.

Main Outcome Measures: Prostaglandin-abortion interval and side effects.

Results: There were no significant differences in median prostaglandin-abortion interval between gemeprost (6.6 hours 95% CI 6.0-10.7) and misoprostol (6.1 hours 95% CI 5.5-7.5) (P = 0.22). The cumulative abortion rates at 24 hours (96% vs 94%, respectively), the surgical evacuation rates (12% and 10%) and the incidence of vomiting, diarrhoea and pain were similar.

Conclusion: Two hundred milligrammes of mifepristone followed 36-48 hours later by either vaginal gemeprost or misoprostol is a highly effective way of inducing abortion in the second trimester of pregnancy.