A randomized trial of oral misoprostol in premenopausal women before hysteroscopy.

OBJECTIVE: To determine if the use of oral misoprostol in premenopausal women undergoing diagnostic hysteroscopy produces a clinically important difference in pre-procedural cervical dilatation.

METHODS: At a tertiary care hospital, premenopausal women undergoing diagnostic hysteroscopy were randomized to receive either 400 microg of misoprostol or a vitamin B6 placebo orally 12 hours before the procedure. Patients were stratified on the basis of parity. The primary outcome was the pre-procedural dilatation of the cervix. Secondary outcomes included the need to further dilate the cervix, the time required to further dilate the cervix, and side effects.

RESULTS: Sixty-four women (11 nulliparous and 53 parous) undergoing diagnostic hysteroscopy consented to participate in the study. Thirty-three women received misoprostol and 31 received placebo. Baseline demographics showed no difference in age and parity between the two groups. There were no significant differences in pre-procedural dilatation (5.0 mm vs. 4.7 mm, P = 0.52), need to further dilate the cervix (56.7% vs. 63.0%, P = 0.63), and time required to further dilate the cervix (12.7 seconds vs. 25.7 seconds, P = 0.27). Significantly more women in the misoprostol group experienced menstrual-like cramping (24.2% vs. 3.3%, P = 0.03) and vaginal spotting (21.2% vs. 3.3%, P = 0.05).

CONCLUSION: In premenopausal women, there is no improvement in pre-procedural cervical dilatation with administration of oral misoprostol 12 hours before diagnostic hysteroscopy. Further research is required in both nulliparous and parous premenopausal women to determine whether oral misoprostol improves cervical dilatation and, if so, the ideal dose, route and timing.