RCT of Cervical Ripening Double Ballon Catheter Prior to Dilation and Evacuation.

This study is a two-arm, non-blinded, randomized controlled trial of a cervical ripening double balloon (CRDB) catheter compared to osmotic dilators (e.g., laminaria and/or Dilapan-S) for overnight cervical preparation prior to dilation and evacuation (D&E). The primary outcome will be mean cervical dilation as assessed by the physician immediately prior to D&E.

Established patients will be approached by a member of the research team about study participation after they have provided informed consent for D&E. Allocation to the study group will be based on a 1:1 blocked randomization scheme. The participant will be informed of their assignment immediately prior to their cervical preparation procedure. Neither the physician nor the patient will be blinded to the assignment as this is not feasible given the differences in interventions.

• Intervention Group: The physician will place a CRDB catheter as directed by the manufacturer's user guide. The uterine balloon of the CRDB catheter will be inflated with 20-40 mL of saline based upon the participant's tolerance.
• Control Group: The physician will place osmotic dilators in the standard fashion. The number of dilators and use of laminaria, Dilapan-S, or a combination will be determined by physician preference.

On the day of the D&E procedure, the physician will remove the cervical dilating device and measure the patient's cervical dilation. Additional data will be collected on the following items.

• Need for and amount of mechanical dilation
• Total procedure time will be calculated in minutes based on the procedure start and stop times recorded in the patient's electronic medical record.

Inclusion criteria

• Singleton pregnancy between 19 weeks 0 days to 23 weeks 6 days GD.
• Planning to undergo D&E with Yale Family Planning and has undergone standard informed clinical consent counseling for the procedure and signed the clinical procedure consent form.
• Stated willingness to comply with all study procedures and availability for the duration of the active part of the study.
• English- or Spanish-speaking individual.
• Residents of the state of Connecticut.

Exclusion criteria

• Spontaneous or induced fetal demise.
• Multiple pregnancy.
• Preterm prelabor rupture of membranes (PPROM).
• Intraamniotic infection.
• Active genital tract infection.
• Active vaginal bleeding.
• Placenta previa or vasa previa.
• Placenta accreta spectrum.
• History of >3 cesarean deliveries.
• BMI >45 kg/m2.
• Contraindication to osmotic cervical dilator or CRDB catheter use as determined by the physician.
• Contraindication to medication used during standard of care cervical preparation.