Optimal timing of misoprostol administration in nulliparous women undergoing office hysteroscopy: a randomized double-blind placebo-controlled study

Objective To determine the optimal timing of vaginal misoprostol administration in nulliparous women undergoing office hysteroscopy. Design Randomized double-blind placebo-controlled study. Setting University teaching hospital. Patient(s) One hundred twenty nulliparous patients were randomly allocated in a 1:1 ratio to the long-interval misoprostol group or the short-interval misoprostol group. Intervention(s) In the long-interval misoprostol group, two misoprostol tablets (400 μg) and two placebo tablets were administered vaginally at 12 and 3 hours, respectively, before office hysteroscopy. In the short-interval misoprostol group, two placebo tablets and two misoprostol tablets (400 μg) were administered vaginally 12 and 3 hours, respectively, before office hysteroscopy. Main Outcome Measure(s) The severity of pain was assessed by the patients with the use of a 100-mm visual analog scale (VAS). The operators assessed the ease of the passage of the hysteroscope through the cervical canal with the use of a 100-mm VAS as well. Result(s) Pain scores during the procedure were significantly lower in the long-interval misoprostol group (37.98 ± 13.13 vs. 51.98 ± 20.68). In contrast, the pain scores 30 minutes after the procedure were similar between the two groups (11.92 ± 7.22 vs. 13.3 ± 6.73). Moreover, the passage of the hysteroscope through the cervical canal was easier in the long-interval misoprostol group (48.9 ± 17.79 vs. 58.28 ± 21.85). Conclusion(s) Vaginal misoprostol administration 12 hours before office hysteroscopy was more effective than vaginal misoprostol administration 3 hours before office hysteroscopy in relieving pain experienced by nulliparous patients undergoing office hysteroscopy. Clinical Trial Registration Number NCT02316301.