Second trimester abortion with prostaglandin F2 alpha

A clinical trial comparing 40-mg and 50-mg, intraamniotic dose schedules of prostaglandin F2 alpha (PGF2 alpha) is described. The trial included 48 patients at 15-20 weeks' gestation, with 20 receiving a 40-mg dose of PGF2 alpha and 28 receiving a 50-mg dose of PGF2 alpha. The success rates for the two groups were 85% and 93%, respectively. All nulliparous patients who had 50 mg of PGF2 alpha and all multiparous patients who had 40 mg of PGF2 alpha aborted within the 48-hour trial period. The mean induction-to-abortion interval with the 50-mg dose was two hours shorter than that with the 40-mg dose. All patients who had 40 mg of PGF2 alpha over 16 weeks' gestation aborted within the trial period. In patients who had 50 mg of PGF2 alpha, the period of gestation did not influence the induction-to-abortion interval. Minor side effects, primarily vomiting or diarrhea, were observed in 65% and 93% of the patients who had 40-mg and 50-mg doses, respectively. We conclude that intraamniotic administration of 50 mg of PGF2 alpha successfully induces midtrimester abortion in nulliparous patients, whereas a 40-mg dose suffices for multiparous women.