In 2115 women seeking voluntary termination of pregnancy after 49 days of
amenorrhea or less, we studied the effect of a single 600-mg dose of
mifepristone (
RU 486), followed 36 to 48 hours later by the administration of one of two
prostaglandin analogues, either
gemeprost (1 mg by
vaginal suppository) or
sulprostone (0.25, 0.375, or 0.5 mg by
intramuscular injection). The women were monitored for four hours after
prostaglandin administration. Efficacy was indicated by the complete expulsion of the conceptus without the need of an additional procedure. All other results were considered failures, and the pregnancy was then terminated by a surgical method. The overall efficacy rate was 96.0 percent (95 percent confidence interval, 95.0 to 96.8). The failures included persisting pregnancies (1.0 percent), incomplete expulsions (2.1 percent), and the need for
hemostatic procedure (0.9 percent). The mean time to expulsion was significantly shorter when
sulprostone was given in the high dose (4.5 hours) than when it was given in the two lower doses (13.1 and 19.3 hours) or when
gemeprost was given (22.7 hours). The mean duration of
uterine bleeding was 8.9 days (range, 1 to 35); one woman received a
blood transfusion. Most women had transient
abdominal pain after receiving
prostaglandin, but there were few other side effects. We conclude that the administration of
mifepristone followed by a small dose of a
prostaglandin analogue is an effective and safe method for the early termination of pregnancy.