Objectives: This study was undertaken to determine whether the addition of extra-amniotic saline infusion improves the efficacy of the Foley catheter in women undergoing cervical ripening and induction of labor with an unfavorable cervical examination.
Study design: One hundred consenting women with a Bishop score less than 5 with singleton gestation, intact membranes, vertex presentation, who required induction of labor were randomly assigned to 2 groups: Foley alone (Foley, n=49) or to the Foley catheter with extra-amniotic saline infusion (EASI, 30 mL of NS per hour infused through the distal port of the Foley, n=51). All women received concurrent dilute oxytocin infusion per protocol. The primary analysis was intent to treat. Nonparametric tests were used as indicated.
Results: At randomization, the groups were well balanced for potential confounders including: parity, gestational age, prior cesarean delivery, preeclampsia, mean dilation, effacement, and Bishop score. There were no differences between the groups for time to delivery (Foley 17.7 +/- 10.5 hours vs EASI 17.4 +/- 11.7 hours, P=.9), the proportion of women delivered before 24 hours (Foley 41/49 [84%] vs EASI 39/51 [77%], P=.37) or cesarean rates (Foley 9/49 [17.7%] vs EASI 9/51 [18.4%], P=.92). There were also no differences in complications, including chorioamnionitis, endometritis, and neonatal morbidity.
Conclusion: EASI does not increase the efficacy of cervical ripening and induction of labor with a Foley catheter and concurrent oxytocin infusion.