Cook Balloon vs Dilapan-S for Outpatient Cervical Ripening

Upon presentation for cervical ripening appointment, a sterile vaginal exam will be completed to assign Bishop score, as per standard routine. Once the patient has been consented and randomized, the participant will have a Cook catheter or Dilapan-S inserted. For the Cook catheter, the uterine component of the balloon will be inflated to maximum 60mL, the vaginal balloon will not be inflated per standard practice and per the literature that shows slightly increased pain and negligible improvement in cervical ripening. The catheter will be taped to the inner thigh with gentle traction. For Dilapan-S, 3-5 dilators will be placed.

After placement, the patient will be discharged home with strict return precautions per the outpatient cervical ripening protocol. Patients must return to labor and delivery within 24 hours of cervical ripening agent placement at their scheduled inpatient induction time.

Upon return to labor and delivery, if not already expelled, the mechanical ripening device will be removed, and an examiner blinded to the cervical ripening method will complete a sterile vaginal exam to assign a Bishop score.

At that point health care providers will manage active labor per usual practice. Labor interventions are at the discretion of the healthcare provider. The need for operative delivery or cesarean section will be at the discretion of the healthcare provider.

Inclusion criteria

• 18-50 years of age
• Term (37-41 6/7 weeks gestational age)
• Low risk (i.e. without any maternal or fetal co-morbidity) and who are candidates for outpatient cervical ripening per the Brigham and Women's outpatient cervical ripening protocol
• Singleton pregnancy
• Cephalic presentation

Exclusion criteria

• Prior cesarean section
• Any contraindication to outpatient cervical ripening per Brigham and Women's outpatient cervical ripening protocol
• Non-English-speaking