A Randomized Controlled Trial of Foley Catheter, Extra-Amniotic Saline Infusion and Prostaglandin E2 Suppository for Labor Induction

OBJECTIVE: The aim of this study is to further compare the efficacy of PGE2 suppository, the intracervical foley catheter and extra-amniotic saline infusion in nulliparous women referred for labor induction. MATERIALS AND METHODS: Totally 368 nulliparous women with a Bishop score ≤ 4 with singleton gestation, vertex presentation and intact membrane referred for labor induction were randomly assigned to 3 groups; Foley catheter alone, Extra-amniotic saline infusion (EASI) and PGE2 suppository. All women received concurrent dilute oxytocine infusion. The change in the Bishop Score, labor progress, various labor endpoints and outcomes of labor were assessed. RESULTS: From 363 women studied after exclusion of 5, 119 were assigned to EASI, 121 to Foley and 118 to PGE2. Patients’ demographics did not differ significantly between three groups nor did indication for induction (P = 0.0001). The EASI group had a significant improvement in Bishop Score 6 hours after induction. The mean time to active phase was 357±135min for EASI,457±178 for Foley and 609±238 min for PGE2 group respectively (P < 0.05).rate of spontaneous rupture of membranes was higher in the EASI group (P = 0.0001) and the mean time from the start of induction up to spontaneous rupture of membranes in the EASI group was shorter than other group(P < 0.05). The mean time to vaginal delivery was 14.8±6.1 in EASI group,11.4±4.8 in Foley and 18.9±6.4 in PGE2 group(P < 0.05).there were no differences in Apgar scores, mean neonatal birth weight and neonatal morbidity. CONCLUSION: Our study showed that pre-induction cervical ripening by EASI with concurrent oxytocin is better than Foley and PGE2 in Bishop score and various labor end point and outcomes.