摘要Objective To investigate the relationship and potential pathways between metal(loid)exposure and the risk of polycystic ovary syndrome(PCOS)in women of childbearing age.Methods This case-control study included 200 patients with PCOS(cases)and 896 non-PCOS controls with the age of 25-37 years.The concentrations of 29 metal(loid)s in the follicular fluid(FF)and clinical indicators in the serum were measured in all participants.Logistic regression analysis and mediation analysis were conducted to evaluate the associations between metal(loid)exposure and PCOS risk and investigate the possible roles of clinical indicators,respectively.Results Logistic regression analysis revealed an association between high copper levels in FF and increased PCOS risk(highest vs.lowest quartile:adjusted odds ratio=2.94,95%confidence interval:1.83-4.72).A high luteinizing hormone/follicle-stimulating hormone ratio and elevated levels of testosterone and anti-Müllerian hormone(AMH)were strongly associated with increased PCOS risk induced by high copper exposure.The mediation analysis indicated a mediating effect of AMH in the association between copper exposure and PCOS risk.Conclusion Copper may affect PCOS risk through the hypothalamic-pituitary-ovarian axis,mediated by AMH.Copper exposure and internal AMH levels are important indicators for early warning of PCOS development.