Effect of Evening Primrose oil on the frequency of uterine contractions and maternal vital signs in post-term pregnancies: A Clinical Trial

Background: One of the possible causes of post-term pregnancies is the unpreparedness of the cervix. Objectives: The present study was designed to investigate the effect of evening primrose oil on the frequency of uterine contractions and maternal vital signs in post-term pregnancies.Methods: The present study was a randomized, double-blinded clinical trial that was conducted on ۱۳۰ pregnant women with post-term pregnancy. The samples were selected by the convenience sampling method, then randomly assigned to two groups (Misoprostol and evening primrose) and (Placebo and Misoprostol). The data collection procedure was done by a checklist of demographic and clinical information along with questions associated with Bishop's score, uterine contractions, and maternal vital signs. The data analysis procedure was done by applying the SPSS version ۲۱ software and descriptive statistics and inferential tests.Results: The Bishop score means in the evening primrose and misoprostol group in comparison with the placebo and misoprostol group showed a meaningful increase (p=۰.۰۰۰۱). However, there was no statistically significant difference in the two groups (p>۰.۰۵) considering uterine contractions during the first six hours after the intervention and the maternal vital signs during the first hour after the intervention.Conclusions: Results of this study showed that using evening primrose oil vaginal capsules along with misoprostol is much more effective in treating the cervix and increasing Bishop's score compared to misoprostol alone. It does not also disturb uterine contractions and maternal vital signs.

Keywords:

evening primrose , misoprostol , vital signs , uterine contractions , cervical ripening