THE ABORTIFACIENT EFFECT OF MISOPROSTOL IN THE 2ND TRIMESTER - A RANDOMIZED COMPARISON WITH GEMEPROST IN PATIENTS PRETREATED WITH MIFEPRISTONE (RU486)

The objective of this work was to study the abortifacient effects of misoprostol, an orally active prostaglandin E1 (PGE1) analogue, in the second trimester. A randomized study of two prostaglandin regimens in women pre-treated with the antiprogesterone mifepristone was carried out in the gynaecological wards of Aberdeen Royal Hospitals, NHS Trust, and included 60 women at 13-20 weeks' gestation, in whom termination of pregnancy had been agreed. Following pre-treatment with mifepristone 600 mg women were randomly allocated to one of two prostaglandin regimens which started 36-48 h later. The first misoprostol 400 mug orally (up to three doses) followed by gemeprost vaginal pessary 1 mg up to two doses. The second was gemeprost vaginal pessary 1 mg up to five doses. The main outcome measures were success rate induction-to-abortion interval and side-effects. There were no significant differences between the two groups in any of the main outcome measures. We conclude that misoprostol is a stable, cheap PGE1 analogue with demonstrable efficacy and acceptable side-effects in the management of second trimester abortion. Further work is needed to establish the optimum dose and regimen.