A comparison of two dosing regimens of intravaginal misoprostol for second-trimester pregnancy termination

OBJECTIVE: To compare the effectiveness of misoprostol administered intravaginally every 6 versus every 12 hours for termination of second-trimester pregnancies. METHODS: One hundred pregnant women at 12-22 weeks' gestation were randomized to receive 200 microg of misoprostol intravaginally either every 6 or every 12 hours for up to 48 hours. RESULTS: The incidences of abortion within 48 hours after initial drug administration were 87.2 and 89.2%, the complete abortion rates 43.9 and 33.3%, and the mean abortion intervals 13.8 and 14.0 hours in the 6- and 12-hour groups, respectively. Side effects were similar between groups. CONCLUSION: Misoprostol administered vaginally is effective for terminating second-trimester pregnancies. Shortening the dosing interval from 12 to 6 hours produced no significant benefit.