Objective: The objective was to investigate mifepristone as a potential adjunct to cervical preparation for surgical abortion after 19 weeks of gestation, with the aim of improving procedure access, convenience and comfort.

Methods: This is a site-stratified, block-randomized, noninferiority trial of 50 women undergoing surgical abortion between 19 and 23 6/7 weeks of gestation randomized to receive either one set of osmotic dilators plus mifepristone the day prior to procedure (mifepristone group) or two sets of osmotic dilators (placed 18–24 h apart) in the 2 days prior to procedure (control group). All subjects received preprocedure misoprostol. Primary outcome was procedure time. Secondary outcomes included preoperative cervical dilation, ease of procedure, and side effects and pain experienced by subjects.

Results: Mean gestational age was similar between groups (20 weeks); more nulliparous subjects were randomized to the mifepristone group (46% vs. 12%, p=.009). Mean procedure times were similar: mifepristone group 11:52 (SD 5:29) vs. control group 10:56 (SD 5:08); difference in means −56 s, with confidence interval (95% CI −4:09 to +2:16) not exceeding the 5-min difference we a priori defined as clinically significant. Preprocedure cervical dilation did not differ and was >3 cm for the majority of subjects in both groups. There was no difference (p=.6) in ease of procedure reported by providers. Preoperative (postmisoprostol) pain and postoperative pain levels were greater with mifepristone (p = 0.02 and p= 0.04 respectively). Overall subject experience was not different (p=0.80), with most reporting a “better than expected” experience.

Conclusions: Mifepristone with one set of osmotic dilators and misoprostol did not result in longer procedure times or less cervical dilation than serial (two sets) of osmotic dilators and misoprostol, and has the potential to improve access to second trimester abortion without compromising safety.

Implications: Use of mifepristone for cervical preparation before surgical abortion after 19 weeks allows for fewer visits and fewer osmotic dilators without compromising cervical dilation or increasing procedure time.