The Effects of Oral and Vaginal Administration of Evening Primrose Oil on Cervical Ripening and Birth Outcomes: A Systematic Review and Meta-Analysis
نویسندگان
1 MSC Midwife, Department of Midwifery, AsadAbad School of Medical Sciences, AsadAbad, Iran
2 Assistant Professor in Biostatistics, Department of Biostatistics, School of Heath, Social Determinants of Health Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
3 MSc of Midwifery, School of Nursing and Midwifery, Mashhad University of Medical Sciences, Mashhad, Iran
4 PhD, Monash Nursing and Midwifery, Monash University, Melbourne, VIC, Australia
5 PhD, Nursing and Midwifery Care Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
6 Assistant Professor, Department of obstetrics and gynecology, School of medicine, Lorestan University of Medical Sciences, Lorestan, Iran
7 Master of Epidemiology, Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
doi
10.22038/ebcj.2026.92015.3205چکیده
Background: Given the conflicting results of three previous systematic reviews, drawing definitive conclusions about the effect of primrose oil on cervical ripening remains challenging.Aim: This meta-analysis aimed to identify and evaluate studies that have examined the effects of oral and/or vaginal evening primrose oil on cervical ripening and birth outcomes.Method: A comprehensive search of English and Persian articles from May 1990-March 2023 was performed in the PubMed, Web of Science, Cochrane Library, Scopus, SID and Magiran databases to identify randomized, placebo, controlled trials (RCTs) of primrose oil.Results: In the review of 16 RCTs, the results revealed a significant difference in the duration of the second phase of labor in the oral EPO capsule (mean difference (MD) = -9.68, 95% confidence interval (CI): -17.23, -2.14, I2 = 0%). Three studies reported significantly higher Bishop scores for the vaginal capsule in the EPO group than in the placebo group (MD=1.81, 95% CI: 0.24; 3.38, I2=100%). Three studies reported significant improvements in 5-minute Apgar scores with the use of the EPO vaginal capsule (MD = 0.60; 95% CI: 0.49, 0.71). Cesarean section rates were significantly lower in the group given vaginal EPO (odds ratio (OR) = 0.62; 95% CI: 0.40–0.96; I2 = 0.1%).Implications for Practice: Oral EPO shortens the duration of the second phase of labor and reduces cesarean section rates but does not yield a noteworthy increase in the Bishop score. Vaginal EPO seems to affect cervical ripening, reduce cesarean section rates, and improve 5-minute Apgar scores.
