Comparison of the Effects of Vaginal Hyoscine Butylbromide and Misoprostol on Cervical Preparation for Gynecological Intrauterine Interventions: A Double-Blind Clinical Trial

Effective cervical preparation is crucial for procedures requiring transcervical uterine access. Insufficient dilation can complicate these interventions. While chemical agents are commonly used, the optimal method remains under investigation. This study aimed to compare the effectiveness and safety of vaginal hyoscine butylbromide versus vaginal misoprostol for cervical preparation prior to gynecological intrauterine surgery. This double-blind, randomized controlled trial included 71 women scheduled for gynecological intrauterine interventions requiring cervical preparation. Participants were randomly assigned to receive either vaginal hyoscine butylbromide (n=36, 40 mg total dose) or vaginal misoprostol (n=35, 200 µg) 2-4 hours before the procedure. The primary outcome was the diameter of the first Hegar dilator that could be inserted through the internal os without resistance. Secondary outcomes included cervicovaginal-uterine complications and drug-related side effects. The mean diameter of the first dilator passed without force was (4.91 ± 1.10) mm in the hyoscine group and (5.54 ± 1.50) mm in the misoprostol group; this difference was not statistically significant (P = 0.081). Notably, the incidence of uterine pain and cramping was significantly lower in the hyoscine group (0% vs. 34.3%, P < 0.001), representing a key clinical advantage. No significant differences were observed in other complications or side effects between the groups. No cases of uterine or cervical rupture occurred. Vaginal hyoscine butylbromide demonstrated comparable cervical dilation to misoprostol but resulted in significantly less uterine pain and cramping, which constitutes a meaningful clinical advantage. The complete elimination of uterine cramping in the hyoscine group highlights its distinct benefit as a cervical priming agent. Hyoscine appears to be a safe and more comfortable option for cervical preparation in premenopausal women undergoing gynecological procedures.