Vaginal misoprostol prior to insertion of an intrauterine device: an RCT

Misoprostol is an agent that may ripen the cervix in nonpregnant women. Here, we investigate whether vaginal misoprostol administered prior to intrauterine device (IUD) insertion reduces the number of failed insertions, insertion-related complications and pain during insertion.

We conducted a double-blinded, multicenter randomized controlled trial among patients requesting an IUD. Nulli- and multi-parous women were included, and both copper-containing and levonorgestrel-releasing IUDs were used. Participants were allocated to either 400 μg misoprostol or placebo (administered 3h prior to IUD insertion). The primary outcome measure was failed insertion. Secondary outcome measures were insertion-related complications, pain, difficulty of insertion and side-effects.

Two hundred and seventy participants were randomized. After drop out for various reasons (mainly no show), 199 participants had an IUD inserted; 102 received misoprostol and 97 received placebo. Only three insertions failed; two in the misoprostol group and one in the placebo group [P = 0.59, relative risk (RR) 1.9, 95% confidence interval (CI) 0.2-20.6]. The overall incidence of insertion-related complications was 21.8% in the misoprostol versus 19.1% in the placebo group (mainly vasovagal-like reactions) and did not differ between groups (P = 0.65, RR 1.1, 95% CI 0.7-2.0). No difference in pain scores between groups was found. Side-effects were more common in the misoprostol group (P = 0.05, RR 1.3, 95% CI 1.0-1.7).

The study showed no benefit for use of misoprostol prior to IUD insertion. However, there is a tendency of possible harm regarding side-effects. Therefore, we would not recommend standard pretreatment with misoprostol. The trial was registered in the European Clinical Trials Database EudraCT 2006-006897-60.