A randomized controlled trial of evening primrose oil for cervical priming prior to operative hysterroscopy

ABSTRACT

Objective: The purpose of this study was to determine the efficacy of Evening Primrose Oil as a cervical ripening agent when used prior to operative hysteroscopy. Study Design: A randomized, double-blind, placebo-controlled trial included a total of 42 patients randomly assigned to the Evening Primrose Oil group (24) and to the placebo group (18). The primary outcome was initial cervical dilatation prior to hysteroscopy. The number of patients requiring cervical dilatation and duration of cervical dilatation to Hegar dilator size 10 were included as secondary outcomes. Results: There was a statistical and clinically significant difference between the initial cervical dilatation in the treatment and placebo groups (7.81 mm vs. 4.33mm). All patients in the placebo group required cervical dilatation prior to hysteroscopy while only 47.62 percent of patients in the treatment group required any dilatation. It took an average of 53.56 seconds to dilate the cervix to Hegar size 10 in the placebo group compared to 17.43 seconds in the treatment group. Conclusion: Similar to trials in pregnant patients, this study proved that Evening Primrose Oil can be used as a cervical priming agent prior to gynecologic procedures.