Mifepristone and misoprostol compared to osmotic dilators for cervical preparation prior to surgical abortion at 15-18 weeks' gestation: A randomised controlled non-inferiority trial.

Paris AE, Vragovic O, Sonalkar S, Finneseth M, Borgatta L.

BMJ Sexual & Reproductive Health
Nov 2019


Cervical preparation is recommended prior to second-trimester surgical abortion. Osmotic dilators are an effective means to prepare the cervix, but require an additional procedure and may cause discomfort. We compared cervical preparation with mifepristone and misoprostol to preparation with osmotic dilators.

Study design:

A randomised, controlled, non-inferiority trial was performed to compare cervical preparation with mifepristone and misoprostol to preparation with osmotic dilators in women undergoing surgical abortion between 15 and 18 weeks gestation. The medication group (n=29) received mifepristone 200 mg orally 24 hours prior to uterine evacuation and misoprostol 400 μg buccally 2 hours before the procedure. The dilator group (n=20) underwent osmotic dilator insertion 24 hours prior to the procedure. The primary outcome was total procedure time, from insertion to removal of the speculum. Secondary outcomes included operative time (from intrauterine instrumentation to speculum removal), initial cervical dilation, nausea, pain, ease of procedure, and whether participants would choose the same modality in the future.


For mean total procedure time, medication preparation (14.0 min, 95% CI 12.0–16.1) was not inferior to dilators (14.3 min, 95% CI 11.7 to 16.8, p<0.001). Mean operative time and ease of procedure were also similar between groups. More women in the medication group than the dilator group would prefer to use the same method in the future (86% vs 30%, p=0.003).


Prior to surgical abortion at 15–18 weeks, use of mifepristone and misoprostol did not result in longer procedure times than overnight osmotic dilators.