Objectives: The purpose of this study was to compare the efficacy of cervical ripening with 2 Foley catheter balloon volumes.
Study design: Pregnant women admitted for induction of labor with a term singleton gestation were randomly assigned for cervical ripening by a balloon inflated with 30 mL or 80 mL of sterile saline.
Results: Two hundred and three women were included in the analysis. Ripening of the cervix with the larger balloon volume was associated with a significantly higher rate of post-ripening dilatation of 3 cm or more (76.0% vs 52.4%, P < .001). In primiparous women, the larger balloon volume resulted in a significantly higher rate of deliveries by 24 hours (71.4% vs 49%, P < .05), and a significantly less requirement of augmentation with oxytocin (69.3% vs 90.4%, P < .05).
Conclusion: Ripening of the unfavorable cervix in primiparous women with a Foley catheter balloon inflated with 80 mL provided effective more dilatation, faster labor, and decreased need for oxytocin than with a balloon inflated with 30 mL of sterile saline.