Oxidative-antioxidant imbalance in female infertility: evaluation of serum biomarkers and their diagnostic potential

Oxidative stress (OS) is implicated in the pathogenesis of female reproductive disorders and may contribute to infertility. This study evaluated serum OS-related biomarkers and their diagnostic potential in women with different causes of infertility. In this case–control study, 300 women were enrolled, including 250 infertile women with diminished ovarian reserve (DOR), polycystic ovary syndrome (PCOS), tubal factor infertility (TF), endometriosis (EM), or unexplained infertility (UI), and 50 fertile controls. Serum total antioxidant capacity (TAC), superoxide dismutase (SOD) activity, iron (Fe), copper (Cu), and reproductive hormone concentrations were measured. Correlation and receiver operating characteristic (ROC) curve analyses were performed. Compared with fertile controls, infertile women had significantly lower serum TAC levels (p < 0.001) and higher Fe concentrations (p < 0.001). SOD activity and Cu concentrations were also significantly higher among infertile women (p < 0.05). ROC curve analysis showed the best diagnostic performance of TAC to distinguish all subgroups of infertility from fertile controls. Serum Fe levels were negatively and significantly correlated with the levels of TAC. An imbalance between oxidative and antioxidative systems is associated with female infertility. TAC demonstrated the highest discriminative ability and may represent a useful noninvasive biomarker of infertility-associated OS.