The Impact of Melatonin Supplementation on Various Aspects of Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis.

Background and Aims: Polycystic ovary syndrome (PCOS) is a prevalent gynecological condition affecting women of reproductive age, with implications for multiple aspects of women's health. Recent research indicates that melatonin (MLT) may enhance several dimensions of this syndrome via various mechanisms. Consequently, this study was undertaken to systematically evaluate the impact of MLT supplementation on different aspects of PCOS. Methods: According to the PRISMA guideline, we identified studies published between January 2013 and November 4, 2024, through a comprehensive electronic search of several reputable databases, including Web of Science (WoS), PubMed (MEDLINE), ProQuest, Scopus, and Google Scholar, utilizing MESH keywords. A meta-analysis was conducted employing a random-effects model, during which we computed the standardized mean differences (SMDs) along with their corresponding 95% confidence intervals. Results: A total of 12 studies were incorporated into the meta-analysis, encompassing 1590 women diagnosed with PCOS. Among these participants, 710 were assigned to the intervention group, while 692 were placed in the comparison or control group, representing data collected from six countries. The SMD for total antioxidant capacity (TAC), and endometrial thickness were 0.97 [95% CI 0.55; 1.40, p: < 0.001, τ 2: < 0.001], 0.50 [95% CI 0.29; 0.70, p: < 0.01, τ 2: 0.01, I 2: 26.38%]. Also, the risk ratio of clinical pregnancy rate after treatment was 0.38 [95% CI 0.14; 0.62, p: < 0.001, τ 2: 0.01, I 2: 13.03%], and the risk difference of clinical pregnancy rate after treatment was 0.10 [95% CI 0.05; 0.16, p: < 0.001, τ 2: < 0.001, I 2: 0%]. Conclusion: The administration of an appropriate dose of MLT demonstrates a notable impact on TAC, endometrial thickness, and the clinical pregnancy rate. This intervention may assist women with PCOS in effectively addressing the challenges associated with this condition, complementing standard treatment protocols.