Misoprostol prior to inserting an intrauterine device in nulligravidas: a randomized clinical trial

STUDY QUESTION How effective is the vaginal administration of misoprostol in dilating the cervix prior to inserting an intrauterine device (IUD) in nulligravidas? SUMMARY ANSWER The use of misoprostol at a dose of 400 µg administered vaginally 4 h prior to IUD insertion increased the ease of insertion and reduced the incidence of pain during the procedure, although the frequency of cramps increased following misoprostol use. WHAT IS KNOWN AND WHAT THIS PAPER ADDS Misoprostol has been widely used in Obstetrics and Gynecology; however, its usefulness and efficacy in facilitating IUD insertion in nulligravidas have yet to be established. The present study shows that the benefits of misoprostol use prior to IUD insertion include facilitating insertion and reducing pain during the procedure; therefore, weighing up the benefits encountered against the only negative side effect (cramps prior to insertion), these results suggest that misoprostol use should become standard practice to facilitate IUD insertion in nulligravidas. STUDY DESIGN, SIZE DURATION A randomized, double-blind clinical trial was conducted. PARTICIPANTS/MATERIALS, SETTING METHODS Nulligravid women of reproductive age were submitted to IUD insertion between July 2009 and November 2011 at the Instituto de Medicina Integral Prof. Fernando Figueira in Recife, Pernambuco, Brazil. A total of 179 women were randomly allocated to two groups: 86 to receive 400 µg of misoprostol vaginally 4 h prior to IUD insertion and 93 to receive placebo. Risk ratios (RRs) were calculated as measures of relative risk, together with their 95% confidence intervals (95% CI). The number needed to treat (NNT) and the number needed to harm (NNH) were also calculated. MAIN RESULTS AND THE ROLE OF CHANCE Significant differences were found between the groups for all the immediate end points studied, with less difficulty in inserting the IUD [RR = 0.49 (23/86 versus 51/93); 95% CI: 0.33–0.72; P = 0.00005], a lower risk of dilatation