Misoprostol is effective for induction of labor in high risk pregnant women: A randomized controlled trial

Abstract

WOMEN: A RANDOMIZED CONTROLLED TRIAL MICHAEL SCHNEIDER, RISA RAMSEY, LU KAO, KELLY ANGELA BENNETT, University of Tennessee, Maternal Fetal Medicine, Memphis, Tennessee, University of Tennessee, Obstetrics and Gynecology, Memphis, Tennessee, University of Tennessee Health Science Center, Obstetrics and Gynecology, Memphis, Tennessee, Vanderbilt University, Maternal Fetal Medicine, Nashville, Tennessee OBJECTIVE: To test the null hypothesis that administering misoprostol orally or vaginally to high risk pregnant women undergoing labor induction will result in no difference in cesarean delivery rates. STUDY DESIGN: Three hundred and eleven women with medical and obstetrical complications of pregnancy were randomized to receive either misoprostol orally (50 mg) or vaginally (25 mg) every four hours for labor induction. Sample size was calculated using a two-tailed alpha of 0.05 and power [1-b] of 80%. Student’s t test, c and Fisher’s exact tests were used in analysis. Data were analyzed on an intent-to-treat basis. RESULTS: Analysis involved 134 women in the vaginal and 162 women in the oral misoprostol group. There were 41 cesarean deliveries (30.6%) in the vaginal and 59 (36.4%) in the oral group [P = .30, relative risk [RR] 0.86, confidence interval [CI] 0.6-1.1] Cesarean delivery rates for dystocia [P = .97, RR 0.99, CI 0.7-1.3] or non reassuring fetal heart rate tracing [P = .97, RR 0.99, CI 0.5-1.7] were not different based on route of administration. Significantly more women in the vaginal group required only a single dose of misoprostol. [P = .007, RR 1.4, CI 1.1-1.8]. No neonate in this study met ACOG criteria for birth asphyxia. CONCLUSION: Misoprostol is effective for induction of labor in women with medical and obstetrical complications of pregnancy. Vaginal administration may be the preferred route when time to delivery is an important concern.