Aim To compare the efficacy and safety of intravaginal misoprostol 200 µg, 400 µg and gemeprost regimens for second-trimester termination of pregnancy (TOP).

Methods A three- armed randomi sed controlled trial (Clinical Trial Certificate 1100015) where 116 women undergoing second-trimester TOP were given intravaginal misoprostol 200 µ g (n=37), misoprostol 400 µg (n=40) or gemeprost 1 mg (n=39) at 4- hour intervals until abortion occurred with a maximum of five doses.

Results The misoprostol 400 µg group had the highest incidence of successful abortions (92.5%) compared to the misoprostol 200 µg (70.3%; p=0.017) and gemeprost 1 mg (74.4%; p=0.037) within 48 hours. There was no significant difference in abortion rate between misoprostol 200 µg and gemeprost. The misoprostol 400 µg group had the highest incidence of fever (70.0%) compared to misoprostol 200 µg (24.3%; p<0.001) and gemeprost 1 mg (46.2%; p=0.041). The gemeprost group had the highest incidence of diarrhoea (38.5%) compared to misoprostol 400 µg (10.0%; p=0.004) and misoprostol 200 µg (8.1%; p=0.003) groups.

Conclusions Intravaginal misoprostol 400 µ g at 4- hour intervals was the most effective regimen but was associated with a high incidence of fever. Misoprostol 200 µg demonstrated similar effectiveness as gemeprost and had lower incidence of diarrhoea. Gemeprost should not be first line for medical therapy given the cost, storage requirements and lower efficacy.