A randomized trial comparing oral misoprostol with intra-amniotic prostaglandin F2alpha for second trimester terminations.

Objective: To compare the efficacy of oral misoprostol with that of intra-amniotic prostaglandin F2alpha (PGF2alpha) for second trimester pregnancy termination.

Methods: One hundred seventeen women with pregnancies of between 16 and 22 weeks' gestation were randomly assigned after insertion of laminaria to receive either oral misoprostol 400 microg every 4 hours (to a maximum of four doses) or intra-amniotic PGF2alpha 40 mg. The rate of complete abortion within 24 hours was the primary outcome for power analysis. Secondary outcome measures were the rate of dilatation and curettage (D&C) for retained placenta and the rates of fever and gastrointestinal complications.

Results: Patient characteristics were similar in both groups. The rate of complete abortion within 24 hours was similar in the misoprostol (63%) and PGF2alpha (66%) groups. The rate of retained placenta requiring D&C was significantly greater in the PGF2alpha group (22.4% vs. 3.4%, P = 0.002). There were no differences in other maternal morbidities. Parous patients treated with oral misoprostol had a significantly greater rate of complete abortion than nulliparous patients (84% vs. 57%, P = 0.04).

Conclusions: Oral misoprostol is as effective as intra-amniotic PGF2alpha for second trimester pregnancy termination when laminaria is inserted before treatment. Parous patients have a higher success rate than nulliparous patients with use of oral misoprostol. Oral misoprostol is associated with a very low rate of placental retention.