Repeated extra-amniotic administration of prostaglandin F2alpha for midtrimester abortion.

Midtrimester abortion was induced in 94 of 100 patients at 16 to 24 weeks' gestation by the extra-amniotic administration of 1170 microng of prostaglandin F2alpha (PGF2alpha) every 10 minutes. The number of prostaglandin doses varied from 16 to 24 depending on the patient's response to the prostaglandin. The median abortion time was 10.0 hours, and 82.0% of the patients aborted within 24 hours. Overall, 68.0% of the patients failed to expel the placenta within one hour of abortion of the fetus. Vomiting and diarrhea occurred among 42.0 and 17.0% of the patients, respectively. Compared with the intra-amniotic administration of a single 50 mg dose of PGF2alpha, the extra-amniotic procedure was associated with similar side effect rates, a higher rate of incomplete abortion, and a significantly shorter abortion time.