The use of oral misoprostol as a cervical ripening agent in operative hysteroscopy: a double-blind, placebo-controlled trial.

OBJECTIVE: The purpose of this study was to assess the effectiveness of oral misoprostol as a cervical ripening agent when used in operative hysteroscopy.

STUDY DESIGN: This was a double-blind, placebo-controlled trial. Any patient undergoing an operative hysteroscopy (with a 9-mm to 10-mm hysteroscope) was considered eligible for the trial. Patients were randomly allocated, by means of computer-generated numbers, to receive either placebo or 400 microg of misoprostol 12 and 24 hours before surgery. The primary outcome measure in this study was the ease of cervical dilatation as measured by the largest-number Hegar dilator that could be inserted into the cervix without resistance. A subjective assessment of the ease of dilatation was also recorded on a Likert scale. Other demographic data including age, menopausal status, parity, and use of gonadotropin-releasing hormone (GnRH) analogues were also recorded. Adverse effects experienced and any other adverse outcomes were also recorded for each group. Logistic regression analysis was used to compare the two groups.

RESULTS: Two hundred four patients were recruited into the study. There were no differences between the two groups in demographic variables. The misoprostol group demonstrated an increased ease of cervical dilatation (odds ratio [OR] 2.6; CI 1.28-5.29; P =.008). This was also demonstrated in the subgroup of patients who were menopausal or who had been pretreated with a gonadotropin-releasing hormone analog (OR 2.49; CI 1.11-5.58; P =.026), as well as in those who were premenopausal (OR 2.15; CI 1.04 4.45; P =.04). There were no differences between the two groups in the time required for dilatation (P =.08) or ease of dilatation (P =.12). Adverse effects were greater in the treatment group: diarrhea (28% vs 4%; P <.001), cramps (27% vs 1%; P <.0001), and bleeding (26% vs 1.3%; P <.001).

CONCLUSIONS: Misoprostol demonstrates a benefit over placebo in the ease of cervical dilatation in premenopausal and postmenopausal women and in those pretreated with a gonadotropin-releasing hormone analog. Adverse effects were more common in the treatment group but did not preclude the patients from taking the medication.