Transcervical Foley catheter with and without extraamniotic saline infusion for labor induction: a randomized controlled trial

OBJECTIVE: To compare the efficacy of transcervical Foley catheter alone (Foley) to transcervical Foley catheter with extraamniotic saline infusion for labor induction and cervical ripening in women with an unfavorable cervix. METHODS: This was a multicenter, randomized, controlled trial of women presenting for labor induction with a singleton, cephalic fetus, intact membranes, and unfavorable cervix (Bishop score 6 or less). Eligible women were randomly assigned to receive either Foley catheter alone or Foley catheter with extraamniotic saline infusion. All women received concurrent oxytocin administration. The primary study outcome was the induction-to-delivery interval. Secondary outcomes included cesarean delivery, maternal infectious outcomes, and immediate neonatal outcomes. Analysis was by intent to treat. RESULTS: One hundred eighty-eight women met eligibility criteria and were randomly assigned (Foley plus extraamniotic saline infusion, n=97; Foley, n=91). Baseline demographic characteristics, including parity, gestational age, and Bishop score were similar between the study groups. The median induction-to-delivery interval in the extraamniotic saline infusion arm (12.6 hours, interquartile range 9.3-18.8 hours) was similar to that in the Foley arm (13.4 hours, interquartile range 9.6-17.5 hours) (P=. 70). The proportion of women delivered by 24 hours was comparable between groups (delivery 24 hours, extraamniotic saline infusion 89.7%, Foley 87.9%, P=.70), as was the rate of cesarean delivery (Foley 18.7%, extraamniotic saline infusion 27.8%, P=.14). No significant differences were noted between the study groups with respect to rate of chorioamnionitis, endometritis, or immediate birth outcomes. CONCLUSION: In women with an unfavorable cervix, the addition of extraamniotic saline infusion to a transcervical Foley catheter does not improve efficacy for labor induction. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00442663 LEVEL OF EVIDENCE: I.