Adjuvant misoprostol or mifepristone for cervical preparation with osmotic dilators before dilation and evacuation

This study aimed to compare effectiveness and safety of cervical preparation with osmotic dilators plus same-day misoprostol or overnight mifepristone prior to dilation and evacuation (D&E).

We conducted a retrospective cohort analysis of 664 patients initiating abortion between 18 and 22 weeks at an ambulatory health center. We abstracted medical record data from two consecutive 12-month periods in 2017 to 2019. All patients received overnight dilators plus: 600 mcg buccal misoprostol 90 minutes before D&E (period 1); 200 mg oral mifepristone at time of dilators (period 2). Our primary outcome was procedure time. We report frequency of patients experiencing any acute complication, defined as unplanned procedure (i.e., reaspiration, cervical laceration repair, uterine balloon tamponade) or hospital transfer and bleeding complications.

We observed higher mean procedure time in the mifepristone group (9.7 ± 5.3 minutes vs 7.9 ± 4.4, p = 0.004). After adjusting for race, ethnicity, insurance, body mass index, parity, prior cesarean, prior uterine surgery, gestational age, provider, trainee participation, and long-acting reversible contraception initiation, the difference remained statistically significant (relative change 1.09, 95% CI 1.01, 1.17) but failed to reach our threshold for clinical significance. The use of additional misoprostol was more common in the mifepristone group, but the use of an additional set of dilators was not different between groups. Acute complications occurred at a frequency of 4.1% in misoprostol group and 4.3% in mifepristone group (p = 0.90).

We found procedure time to be longer with adjunctive mifepristone compared to misoprostol; however, this difference is unlikely to be clinically meaningful. Furthermore, the frequency of acute complications was similar between groups.

Overnight mifepristone at the time of cervical dilator placement is a safe and effective alternative to adjuvant same-day misoprostol for cervical preparation prior to D&E and may offer benefits for clinic flow and patient experience.