NEW YORK (Reuters Health) – Vaginal misoprostol applied prior to intrauterine device (IUD) insertion does not make the procedure go any easier or lessen the patient’s pain, a Dutch study shows. And because the drug has side-effects, the research team suggests it probably shouldn’t be used at all for this purpose.

Misoprostol causes cervical ripening even in nonpregnant women, and is used prior to hysteroscopy to increase cervical dilatation and lower the risk of cervical laceration, the authors explain in Human Reproduction, published online December 15th.

To test their theory that vaginal misoprostol would make IUD insertion easier and less painful, senior author Dr. Frans M. Helmerhorst, from Leiden University Medical Center, and colleagues conducted a multicenter, double-blinded trial among 199 women. They randomized 102 to misoprostol 400 µg and 97 to placebo, to be administered 3 hours prior to the procedure.

They report three failed IUD insertions (the primary end point), two in the misoprostol group and one in the placebo group. In two cases the clinician could not sound the ostium, and one of the devices had a technical problem. Most were placed during the first attempt (88% with misoprostol and 95% with placebo).

Clinicians who inserted the IUDS — interns, residents, midwives and gynecologists – reported no less difficulty with insertion after misoprostol. The authors note that the experience of the inserter did not affect the number of complications, ease of insertion, or patients’ pain.

Complication rates (vasovagal-like responses, syncope) were similar in the two groups, and there were no instances of perforation, major bleeding or postinsertion infection.

Mean pain scores on a 10-cm visual analog scale were 46 mm in the misoprostol group and 40 mm in the placebo group (p = 0.14).

The only significant difference between groups was a higher rate of side effects with misoprostol (56.6% vs 42.4%, p = 0.05). There was a nonsignificant trend toward more abdominal cramping with the active drug (44.4% vs 31.5%, p = 0.07). Other than that, no single adverse reaction occurred with any greater incidence with either treatment.

Dr. Helmerhorst and colleagues did note that nulliparous women had significantly higher pain scores and more frequent vasovagal-like reactions, and clinicians had more difficulty inserting their IUDs, compared with multiparous women (p < 0.001 for all three). However, side-effects of the assigned treatments did not differ based on parity. This study did not show if longer duration of misoprostol pretreatment may have been more effective, nor did it address the effect after a prior failed IUD insertion. Nonetheless, the authors conclude that “routine administration of misoprostol prior to IUD insertion is ineffective and might even cause side-effects.” Reference:
Vaginal misoprostol prior to insertion of an intrauterine device: an RCT

Hum Reprod 2010.