Effects of prophylactic misoprostol administration prior to intrauterine device insertion in nulliparous women

Background: This study was conducted to examine the effects of prophylactic misoprostol prior to intrauterine device (IUD) placement in nulliparous women.

Study design: Nulliparous, reproductive-aged women desiring an IUD for contraception were randomized to receive 400 mcg of buccal misoprostol or placebo 90 min prior to IUD insertion. Subjects completed a series of 100-mm visual analogue scales (VAS, anchors: 0=none, 100 mm=worst imaginable) to measure their perceived pain at several times points (anticipated pain, leg positioning, speculum placement, tenaculum placement, IUD insertion, equipment removal and 5 min postinsertion). Secondary outcomes included provider "ease of placement" (100-mm VAS, anchors: 0=easy, 100 mm=extremely difficult), side effects and retention of the IUD after 1 month (self-report or clinic visit). The study had 80% power (α=0.05, one-sided) to detect a reduction with treatment of 20 mm in VAS scores with a combined sample size of 34.

Results: A total of 40 subjects were randomized to receive either misoprostol or placebo, and 35 completed the study. Five subjects withdrew (four prior to receiving study medication and one declined IUD). Baseline characteristics were similar between groups. There were no significant differences in patient-reported pain with IUD placement [misoprostol 65 mm (SD 21), placebo 55 mm (SD 21), p=.83] or at any other time point. Moreover, the misoprostol group reported significantly more preinsertion nausea (29% vs. 5%, p=.05) and cramping (47% vs. 16%, p=.04) than the placebo group. While provider-reported ease of insertion was not significantly different between groups, three placebo patients required additional dilation vs. none in the misoprostol group. All 35 subjects underwent follow-up at least 1 month postinsertion, and no expulsions were reported.

Conclusion: Prophylactic misoprostol prior to IUD placement in nulliparous women did not reduce patient perceived pain, but it did appear to increase preinsertion side effects.