Preinduction cervical ripening techniques compared

To assess the clinical efficacy of pharmacologic, mechanical and combination techniques of cervical ripening.

From March 1997 to August 1998, all cervical-ripening patients at Lehigh Valley Hospital were randomly assigned to three groups: intravaginal misoprostol, intracervical Foley catheter, or combination prostaglandin E2 (PGE2) gel and Foley catheter. Inclusion criteria included Bishop score < or = 5 and no contraindication to labor. The remaining delivery process was actively managed according to established guidelines. Multiple variables in perinatal outcome were analyzed, with the cesarean section rate and time from ripening to delivery as the main outcome variables.

Of the 205 patients, 65 were randomized to the misoprostol group, 71 to the Foley group and 69 to the catheter-and-gel group. There were no differences between groups in delivery indications, maternal demographics, ultrasound findings, labor interventions, intrapartum times, mode of delivery, postpartum complications or neonatal outcomes. The misoprostol group demonstrated a higher rate of uterine tachysystole and required oxytocin less when compared to the two catheter groups.

The higher rate of uterine tachysystole with misoprostol did not increase the cesarean section rate. The higher rate of oxytocin required by the two catheter groups did not increase the delivery time intervals. There appears to be no benefit to adding intracervical or intravaginal PGE2 gel to the intracervical Foley balloon. The misoprostol and catheter ripening techniques have similar safety and efficacy.