A comparison of vaginally administered misoprostol with extra-amniotic saline solution infusion for cervical ripening and labor induction

Abstract

Objective: The purpose of this study was to compare intravaginal misoprostol with extra-amniotic saline solution infusion with concomitant oxytocin for cervical ripening and labor induction in viable pregnancies.

Study design: Two hundred women with indications for labor induction and unfavorable cervices were assigned randomly to vaginal misoprostol or extra-amniotic saline solution infusion. Twenty-five micrograms of misoprostol was administered every 4 hours up to six doses, followed by intravenous oxytocin administration. Patients who had received extra-amniotic saline solution infusion also received intravenous oxytocin along with a maximum 12-hour saline solution infusion through Foley catheters that were placed above the internal cervical os.

Results: One hundred women were randomly assigned to misoprostol, and 100 women were assigned randomly to extra-amniotic saline solution infusion. The average interval from start of induction to vaginal delivery was longer in the misoprostol group (1323.3 +/- 700.3 minutes) than in the extra-amniotic saline solution infusion group (970.4 +/- 502.7 minutes; P =.006, log transformed data). Abnormal fetal heart rate tracings were found in 30% of the patients who received misoprostol and in 19% of the patients who received extra-amniotic saline solution infusion (relative risk, 1.6; 95% CI, 1.0-2.4; P =.05). There was more tachysystole in the misoprostol group (8%) than in the extra-amniotic saline solution infusion group (1%; P =.02). There were no differences in the routes of deliveries or neonatal outcomes between groups.

Conclusion: Extra-amniotic saline solution infusion with oxytocin administration appears more effective and is associated with fewer maternal complications than misoprostol for cervical ripening and labor induction.