Background: As an important diagnostic and therapeutic procedure for patients with intrauterine diseases, hysteroscopy permits a good view of the uterine cavity, thereby increasing diagnostic accuracy. Complications often encountered during hysteroscopy primarily concern problems with cervical dilatation and include uterine perforation, cervical tears, and the creation of false tracts. In this study, we investigate the utility of vaginal misoprostol for cervical dilatation in women undergoing hysteroscopy.

Methods: This triple-blind, randomized, placebo-controlled study was carried out at Mirza Khoochak Khan Hospital, Tehran, Iran. We excluded women who were pregnant, had genital tract infection, or history of cervical trauma. We randomly assigned 80 women with abnormal uterine bleeding or intrauterine lesions to receive either 200 μg vaginal misoprostol or placebo. Ten to twelve hours prior to hysteroscopy, the placebo or misoprostol was administered to the posterior vaginal fornix. Data regarding cervical response and outcome of operative hysteroscopy, as well as complications, were analyzed.

Results: The mean cervical width, as estimated by Hegar dilator, was significantly greater in the treated group (7.8±1.6mm) than that in the control group (5.6±2.2mm, p<0.001). In the misoprostol group, 28 (70%) patients required cervical dilatation, compared with 38(95%) in the placebo group (p=0.001). A significantly shorter median time of cervical dilatation to Hegar number 9 was found in the treated subjects than in the controls (60 vs. 180 seconds, p<0.001). The mean operative time was significantly shorter in the treated group (8.8±8.7 minutes) compared with that of the control group (13.1±10.1 minutes, p=0.043).

Conclusions: Vaginal misoprostol before operative hysteroscopy lessens the need for cervical dilatation, facilitating hysteroscopic surgery.