Labor induction in women with an unfavorable Bishop score: randomized controlled trial of intrauterine Foley catheter with concurrent oxytocin infusion versus Foley catheter with extra-amniotic saline infusion with concurrent oxytocin infusion.

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.