Effectiveness and adverse effects of vaginal misoprostol as a single agent for second trimester pregnancy termination: the impact of fetal viability.

PURPOSE: To compare the effectiveness of vaginal misoprostol for second-trimester termination between pregnancies with a dead fetus in utero and those with a live fetus and to identify factors associated with the success rate. METHODS: Singleton pregnancies with live fetuses and dead fetuses, between 14 and 28 weeks of gestation, with an unfavorable cervix, were recruited to have pregnancy termination with intravaginal misoprostol 400 mcg every 6 h. RESULTS: Misoprostol was highly effective for termination, with a low failure rate of 6.3%. The effectiveness was significantly higher in pregnancies with a dead fetus (log-rank test; p: 0.008), with a median delivery time of 11.2 vs. 16.7 h. Fetal viability, fetal weight or gestational age, and an initial Bishop score were significantly associated with the total amount of misoprostol dosage used for induction. Fetal viability and gestational age/fetal weight were still independent factors after adjustment for other co-factors on multivariate analysis. CONCLUSION: Vaginal misoprostol is highly effective for second-trimester termination, with significantly higher effectiveness in pregnancies with a dead fetus. Also, the effectiveness is significantly associated with birth weight/gestational age, and initial Bishop score.