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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
  1. Amy E Paris1,2,
  2. Olivera Vragovic3,
  3. Sarita Sonalkar4,
  4. Molly Finneseth5,
  5. Lynn Borgatta5
  1. 1 Obstetrics and Gynecology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA
  2. 2 Dartmouth College Geisel School of Medicine, Hanover, New Hampshire, USA
  3. 3 Boston Medical Center, Boston, Massachusetts, USA
  4. 4 Obstetrics and Gynecology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
  5. 5 Obstetrics and Gynecology, Boston University School of Medicine, Boston, Massachusetts, USA
  1. Correspondence to Dr Amy E Paris, Obstetrics and Gynecology, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, USA;{at}


Objective 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.

Results 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).

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

Trial registration number NCT01462.

  • abortion
  • second trimester
  • uterine aspiration
  • dilation and evacuation
  • cervical preparation

Statistics from


  • Contributors LB was the principal investigator; she planned and designed the study, participated in data collection, interpretation of results, and preparation of the manuscript. AP was a co-investigator who participated in subject recruitment, data collection, interpretation of data, and preparation of the manuscript including final submission. SS and MF were co-investigators who collaborated on study design, subject recruitment, data collection, interpretation of results, and manuscript preparation. OV collaborated on study design, devised and performed statistical analysis, data interpretation and participated in manuscript preparation. All authors read and approved the final manuscript.

  • Funding This study was supported by a grant from the Society of Family Planning Research Fund.

  • Competing interests None declared.

  • Patient consent for publication Not required.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Data are available upon reasonable request.

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