Abstract
OBJECTIVE: To examine the relationship between oxidative stress markers and reproductive parameters in women undergoing assisted reproductive treatments, focusing on the interaction between demographic, oxidative, and reproductive factors. METHODS: A total of 49 patients with a mean age of 36.0±3.5years were evaluated. Biomarkers analyzed included reduced glutathione (GSH), disulfide glutathione (GSSG), total glutathione (tGSH), the GSSG/GSH ratio, reactive oxygen species (ROS), and reactive nitrogen species (RNS). Blood and follicular fluid samples were collected and analyzed, correlating these markers with variables such as antral follicle count (AFC), oocytes retrieved, mature oocytes, blastocyst formation, and pregnancy rates. RESULTS: The results showed that AFC is a key marker of ovarian reserve, correlating positively with the number of oocytes retrieved and mature oocytes. Age significantly influenced antioxidant markers in both blood and follicular fluid, with a decline in antioxidant capacity linked to aging. In follicular fluid, higher GSSG levels correlated with the number of oocytes retrieved, indicating increased metabolic activity and ROS generation, thus raising oxidative burden during ovarian stimulation. Additionally, GSH and tGSH levels in blood negatively correlated with mature oocytes, suggesting greater antioxidant consumption during elevated metabolic demand. CONCLUSIONS: Glutathione is a robust and clinically promising redox biomarker for female fertility, evidencing strong correlations between systemic and follicular redox markers. Advancing age and repeated ovarian stimulation were shown to compromise antioxidant capacity, negatively impacting reproductive outcomes. Establishing reference values, particularly for the GSH/GSSG ratio, may enable its use as a prognostic tool, while the quantification of ROS and RNS could support personalized interventions and ovarian stimulation protocols.