Induction of labor by prostaglandin E2: intracervical gel or vaginal pessaries?

To investigate the best route of prostaglandin medication for induction of labor, 125 pregnant women with unfavorable cervices (Bishop scores less than or equal to 6) were randomized to induction of labor with either PGE2 (0.5 mg) in a viscous intracervical gel once daily or PGE2 pessaries (2.5 mg) 1-2 a day. As estimated by life table analysis, the pessaries were significantly more effective inducing vaginal delivery compared to intracervical gel (24 h: P less than 0.025, 48 h: P less than 0.01, logrank test) and vaginal delivery was obtained within 24 h/48 h in 50%/72% of the women in the pessary group and in 29%/55% of the women in the intracervical group. Cervical ripening was found within 3 h (P less than 0.001) and in the subsequent 3 to 24 h period (P less than 0.005) after both treatments, no difference being found between the groups. The pessaries were much more effective inducing regular contractions compared to the intracervical gel (P less than 0.005, logrank test), so the latter seems preferable if cervical ripening rather than induction is intended. No difference was found analyzing the active labor period. No difference was found in methods of delivery, neonatal parameters (Apgar scores, umbilical artery blood pH and standard base excess), and the patients' attitude towards both methods of induction were equally favorable.