Effect of Evening Primrose Vaginal Capsule on Cervix Preparation and Duration of First Stage of Labor in Nulliparous Women Referred to Fatemieh Hospital in Hamadan, Iran: A Single-blind Randomized Controlled Trial

Background: Cervix preparation is one of the main steps in the onset of labor and is very important for success in initiating or inducing labor. Objective: The present study aimed at investigating the effect of evening primrose vaginal capsule on the preparation of cervix and the consequences of labor in nulliparous women. Methods: This randomized clinical trial study was conducted in 2018 on 100 nulliparous women referred to Fatemieh Hospital in Hamadan. In intervention group (50 people), one evening primrose capsule (500 mg) was used vaginally and then two hours later, another capsule was used, and placebo was used in the control group (50 people). Then, the dilatation, effacement, Bishop scores and duration of the first stage of the labor were compared in two groups after 4 hours. Statistical analysis was performed with SPSS 21. The significance level was considered to be 0.05. Results: There was a statistically significant difference in the mean score and standard deviation of dilatation, effacement of cervix, bi-shop scores and duration of the first stage of labor four hours after the intervention in the intervention and Placebo groups by controlling the effect of potential confounding factors (P <0.001). Conclusion: The results showed that the use of evening primrose vaginal capsules can reduce the length of the first stage of labor, improve Bishop score, and soften and ripen the cervix.