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

Abstract

Abstract 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, with unfavorable cervix were recruited to have pregnancy termination with intravaginal misoprostol 400 mcg every 6 hours. 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 median delivery time of 11.2 vs 16.7 hours. Fetal viability, fetal weight or gestational age and an initial Bishop score were significantly related with total amount of misoprostol dosage used for induction. Fetal viability and gestational age / fetal weight were still an independent factor after adjustment 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, suggesting that the regimen of misoprostol should be modified, depending on fetal viability and gestational age.