Background: To evaluate the effects of vaginal misoprostol on cervical dilatation before operative hysteroscopy in pre-menopausal women.
Methods: Four groups of 12 women were randomly assigned to receive either placebo or vaginal misoprostol in doses of 200, 400 or 800 micro g 4 h before the surgical procedure. The number of patients was calculated with an alpha = 0.01 and beta =0.20 for a difference of 50%. The primary outcome measure was cervical width, assessed by the largest size of Hegar dilator that could be inserted without resistance. The secondary outcomes were subjective assessments of the ease of dilatation and pre-operative pain, as well as adverse effects and complications.
Results: There was no difference in the baseline diameter of the cervical opening between the placebo group (6.1 +/- 1.4 cm) and the misoprostol groups (6.3 +/- 2.1 cm). The groups did not differ significantly in the time required for dilatation, ease of dilation, or the number of adverse effects. Pre-operative pain, evaluated by a pain scale, was greater in the treatment groups and was rated at 2.5 +/- 2.3 (P = 0.015), 2.4 +/- 1.2 (P = 0.073) and 2.8 +/- 2.9 (P = 0.012) respectively for each increasing dose group.
Conclusions: Vaginal misoprostol applied 4 h before operative hysteroscopy at three different doses did not reduce the need for cervical dilatation, did not facilitate hysteroscopic surgery, and increased pre-operative pain.