Interconnections between the immune system and infertility in women with polycystic ovary syndrome: a scoping review

To map the existing evidence on the influence of the immune system on infertility in women with polycystic ovary syndrome (PCOS).

This scoping review was conducted in accordance with the Joanna Briggs Institute methodology and reported following the PRISMA-ScR guidelines. Searches were were conducted in January 2025 in PubMed, Embase, Virtual Health Library, LILACS, Web of Science, and Scopus for studies published between 2010 and 2024 in English, Portuguese, and Spanish. Study selection and data extraction were conducted independently by two reviewers. Data were analyzed descriptively and synthesized narratively, supported by charts and figures. This review considered primary studies published between 2010 and 2024 in English, Portuguese, or Spanish involving women of reproductive age with polycystic ovary syndrome, addressing the interplay between immune dysfunction and infertility. Gray literature, duplicate records, animal or in vitro studies, reviews, meta-analyses, and articles not aligned with the review objective were excluded.

A total of 19 studies were included, most of them observational and conducted predominantly in China and Middle Eastern countries. The main markers investigated were inflammatory cytokines, immune cells, and proteins related to oxidative stress. Increased levels of pro-inflammatory cytokines were observed, along with reduced levels of regulatory cytokines, consistently associated with anovulation and reproductive dysfunction. The evidence also demonstrated interactions between chronic low-grade inflammation, hormonal imbalance, and metabolic disturbances, which collectively contribute to impaired ovulatory function and reduced fertility.

Infertility in PCOS is driven by a complex interplay between immune imbalance and endocrine-metabolic dysfunction, with chronic inflammation playing a central role in ovulatory and endometrial impairment. Despite these advances, the predominance of observational evidence and regional concentration of studies restrict broader applicability. These results underscore the need for well-designed research integrating immunological and reproductive pathways to inform more precise therapeutic strategies.