Foley Catheter Compared to the Foley Catheter Alone for Cervical Ripening

Those who provide informed consent will be allocated by an online randomization system either to placement of a transcervical Foley catheter and an intravaginal dinoprostone controlled release insert or a Foley catheter alone. Randomization will be stratified by parity (nulliparous or parous).

In both study groups, the balloon on the end of the Foley catheter will be inflated with 30 mL of sterile water, pulled back against the internal os of the cervix, and taped to the maternal thigh under minimal tension. Also in both groups, the Foley catheter will be removed if any of the following occurs: 1) expulsion, 2) fetal heart rate tracing mandating evaluation for membrane rupture and placement of internal monitors, 3) spontaneous membrane rupture, or 4) if 12 hours has elapsed since placement. The dinoprostone insert will be removed if: 1) the fetal heart rate tracing mandates evaluation for membrane rupture and placement of internal monitors, 2) tachysystole develops (more than 5 contractions per 10 minutes averaged over 30 minutes, 3) spontaneous membrane rupture, or 4) 12 hours has elapsed since placement. Though these are the criteria for insert removal, in keeping with the pragmatic design of this trial, the decision regarding removal will be left to the discretion of the attending physician.

Women will remain recumbent for 30 minutes after agent placement and, except for trips to the restroom, will undergo continuous monitoring of uterine contractions and fetal heart rate. Oxytocin, according to standard intravenous protocol, will be allowed only after removal of cervical ripening agent(s). After specified cervical ripening, labor management will be at the discretion of the attending obstetrician, in keeping with the pragmatic nature of the study design.

Antibiotics will be administered if indicated for prophylaxis against early-onset neonatal infection with group B streptococci or for treatment of chorioamnionitis. Cesarean delivery will be performed, per the discretion of the attending obstetrician, for standard maternal or fetal indications.

Medical records will be reviewed no less than 30 days after delivery. Demographic, intrapartum, and outcome data will be entered into a computerized database.

Inclusion criteria

• Cervix ≤2 cm dilated; if 2 cm, <80% effaced
• Gestational age 37 weeks or more
• Singleton gestation
• Cephalic presentation
• Live fetus

Exclusion criteria

• Contractions more frequent than every 5 minutes
• Premature rupture of membranes
• Prior uterine incision
• Temperature 38C or higher
• Fetal anomalies
• Placenta previa
• Suspected abruption or undiagnosed bleeding more than spotting
• Fetal heart rate tracing prior to enrollment with no more than minimal variability, late decelerations, or more than two variable decelerations
• HIV infection
• Allergy to either latex or dinoprostone