Amniotomy immediately following Foley cervical ripening shortens time to delivery

Reference

Gomez Slagle HB, Fonge YN, Caplan R, Pfeuti CK, Sciscione AC, Hoffman MK. Early vs late artificial rupture of membranes following Foley catheter ripening: a randomized controlled trial. Am J Obstet Gynecol 2022:226(5):724.e1-9.

Synopsis

The authors of this study sought to determine whether amniotomy within 1 hour after Foley catheter cervical ripening for induction of labor would safely shorten time to delivery compared with expectant management. The authors included 160 pregnant women, at least 18 years old (63% nulliparous), with a singleton term pregnancy (37 or more weeks gestational age) in cephalic presentation, who were undergoing induction of labor and requiring cervical ripening. Women were excluded if they had a uterine scar, fetal demise or major known anomaly, or growth restriction, or for several maternal medical conditions. The institutional protocol for cervical ripening was to use Foley catheter placed beyond the internal cervical os and inflated with 30 mL water, then taped to the woman’s thigh at mild tension, plus a 25-mcg tablet of misoprostol placed high in the posterior fornix. Providers could place up to 5 additional doses of misoprostol every 3 hours at their discretion. The Foley catheter was removed at 12 hours if it had not been expelled spontaneously. Induction continued with oxytocin per institutional protocol at provider discretion. At the time of Foley expulsion or removal, eligible women were randomized to receive amniotomy within one hour or expectant management. Amniotomy could be performed at provider discretion for those in the expectant management group with a minimum interval of 4 hours after expulsion (mean = 10 hours). The main outcome was mean time to delivery after Foley catheter expulsion, which was shorter in the early amniotomy group (11.1 hours [95 % CI 6.3 - 7.1] vs 19.8 hours in the expectant management group [CI 13.2-26.2]; P < .001). There were fewer cesarean deliveries in the early amniotomy group, but the number did not reach statistical significance (22% vs 31%; P = .25). There were also no differences in other secondary maternal or neonatal outcomes, including intra-amniotic infection, cord prolapse, endometritis, use of terbutaline, epidural use, or multiple neonatal outcomes.