- To compare the efficacy of two mechanical devices for cervical ripening: Foley catheter with extra-amniotic saline infusion and the Cook cervical ripening balloon. Women at term with a singleton pregnancy who presented for labor induction were randomly assigned to the Foley catheter or the Cook cervical ripening balloon (costs $3 and $41, respectively). The main outcome measures included time from device insertion to delivery, rates of successful vaginal delivery and occurrence of adverse events. The study was completed by 188 women. Time from balloon insertion to expulsion and from insertion to delivery was significantly shorter in the Foley catheter group when compared with the Cook cervical ripening balloon group (6.9 ± 4.2 vs. 10.1 ± 4.7 hours, p = .001 and 19.6 ± 11.4 vs. 23.4 ± 15.5 hours, p = .03, respectively). There were no significant differences in other outcomes. Considering its shorter induction process and lower cost, Foley catheter with extra-amniotic saline infusion is superior to the Cook cervical ripening balloon for initiating cervical ripening.