MisoREST: surgical versus expectant management in women with an incomplete evacuation of the uterus after misoprostol treatment for miscarriage: a randomized controlled trial

Study question: Is curettage more effective than expectant management in case of an incomplete evacuation after misoprostol treatment for first trimester miscarriage?

Summary answer: Curettage leads to a higher chance of complete evacuation but expectant management is successful in at least 76% of women with an incomplete evacuation of the uterus after misoprostol treatment for first trimester miscarriage.

What is known already: In 5-50% of the women treated with misoprostol, there is a suspicion of incomplete evacuation of the uterus on sonography. Although these women generally have minor symptoms, such a finding often leads to additional curettage.

Study design, size, duration: From June 2012 until July 2014, we conducted a nationwide multicenter randomized controlled trial (RCT). Women who had had primary misoprostol treatment for miscarriage with sonographic evidence of incomplete evacuation of the uterus were randomly allocated to either curettage or expectant management (1:1), using a web-based application.

Participants/materials, setting, methods: We included 59 women in 27 hospitals; 30 were allocated to curettage and 29 were allocated to expectant management. A successful outcome was defined as sonographic finding of an empty uterus 6 weeks after randomization.

Main results and the role of chance: Baseline characteristics of both groups were comparable. Empty uterus on sonography or uneventful clinical follow-up was seen in 29/30 women (97%) allocated to curettage compared with 22/29 women (76%) allocated to expectant management (RR 1.3, 95% CI 1.03-1.6) with complication rates of 10% versus 10%, respectively (RR 0.97, 95% CI 0.21-4.4). In the group allocated to curettage, no woman required re-curettage, while two women (6.7%) underwent hysteroscopy (for other or unknown reasons). In the women allocated to expectant management, curettage was performed in four women (13.8%) and three women (10.3%) underwent hysteroscopy.

Limitations, reasons for caution: Due to a strong patient preference, mainly for expectant management, the targeted sample size could not be included and the trial was stopped prematurely.

Wider implications of the findings: In women suspected of incomplete evacuation of the uterus after misoprostol, curettage is more effective than expectant management. However, expectant management is equally safe and prevents curettage for most of the women. This finding could further restrain the use of curettage in the treatment of first trimester miscarriage.

Study funding/competing interests: This study was funded by ZonMw, a Dutch organization for Health Research and Development, project number 80-82310-97-12066. There were no conflicts of interests.

Trial registration number: Dutch Trial Register NTR3310, http://www.trialregister.nl TRIAL REGISTRATION DATE: 27 February 2012.

Date of first patient's enrolment: 12 June 2012.