A comparison of intravaginal misoprostol with prostaglandin E2 for termination of second-trimester pregnancy

Abstract

Background: The most widely used medical method of terminating second-trimester pregnancy is the intravaginal administration of prostaglandin E2 (dinoprostone [PGE2]). This treatment is highly effective but is associated with severe gastrointestinal side effects and hyperpyrexia.

Methods: We conducted a prospective, randomized trial comparing the efficacy and safety of misoprostol, a prostaglandin E1 analogue (200 micrograms intravaginally every 12 hours), with the efficacy and safety of PGE2 (20 mg intravaginally every 3 hours). The study population included 55 pregnant women between 12 and 22 weeks' gestation who were undergoing termination of pregnancy for either intrauterine fetal death (37 women) or medical or genetic reasons (18 women).

Results: The rate of successful abortions within 24 hours was 81 percent (22 of 27 women) with PGE2 and 89 percent (25 of 28 women) with misoprostol (P = 0.47). All the women who received misoprostol had successful abortions within 38 hours. Among those who had an abortion within 24 hours, the mean interval from treatment to abortion was similar in both groups (10.6 hours with PGE2 and 12.0 hours with misoprostol, P = 0.33). The rate of complete abortion, defined as the passage of the fetus and the placenta simultaneously, was 32 percent for PGE2 and 43 percent for misoprostol (P = 0.56). Certain side effects were more frequent in the women receiving PGE2 than in those receiving misoprostol: pyrexia (63 percent vs. 11 percent; P < 0.001), uterine pain (67 percent vs. 57 percent, P = 0.58), vomiting (33 percent vs. 4 percent, P = 0.005), and diarrhea (30 percent vs. 4 percent, P = 0.012). The average cost per treatment was $315.30 for PGE2, as compared with $0.97 for misoprostol.

Conclusions: Misoprostol is at least as effective as PGE2 for the termination of second-trimester pregnancy involving either a dead or a living fetus, but it is less costly, is easier to administer, and is associated with fewer adverse effects.

PIP: At the Los Angeles County--University of Southern California Medical Center, physicians compared data on 27 women who received 20 mg prostaglandin E2 (PGE2) intravaginally every 3 hours to induce a 2nd trimester abortion with data on 28 similar women who received 200 mcg misoprostol intravaginally every 12 hours. The women underwent termination of pregnancy for intrauterine fetal death or medical or genetic reasons. The successful abortion rate within 24 hours was similar for both groups (81% for PGE2 and 89% for misoprostol; p = 0.47). For both groups, the mean intervals between treatment and abortion among women who successfully delivered the conceptus within 24 hours were not statistically different (10.6 hours for PGE2 and 12 hours for misoprostol; p = 0.33). Every woman in the misoprostol group successfully aborted within 38 hours. Passage of the fetus and the placenta simultaneously occurred in 32% of PGE2 cases and in 43% of misoprostol cases (p = 0.56). Women receiving PGE2 were more likely to suffer from a fever (= or 38 degrees Celsius) (63% vs. 11%; p .001), severe pain requiring analgesia medication more than once (26% vs. 4%; p = .025), vomiting (33% vs. 4%; p = .005), and diarrhea (30% vs. 4%; p = 0.012) than women receiving misoprostol. The average number of doses and the average cost per treatment were much higher for PGE2 than for misoprostol (3.7 vs. 1.4 and $315.30 vs. $0.97, respectively). 57% of misoprostol patients had a successful abortion with just 1 dose of 200 mg misoprostol. These findings demonstrate that intravaginal administration of misoprostol is a safe and effective method of terminating 2nd trimester pregnancy, easier to administer and less costly than PGE2.