Figure 1. Experimental Design. Women diagnosed with infertility, with a body mass index (BMI) between 18 and 30 kg/ m² and without high-risk chronic diseases, were included in the study, while patients with infectious diseases, smoking, polycystic ovary syndrome (PCOS), moderate/severe endometriosis, or a history of recurrent pregnancy loss were excluded. Ovarian stimulation followed standard protocols, with medication adjustments based on individual characteristics. Follicular development was monitored via transvaginal ultrasound, and aspiration was performed after triggering with recombinant human chorionic gonadotropin (rhCG), urinary human chorionic gonadotropin (uhCG), and/or gonadotropin-releasing hormone (GnRH) agonist, once follicles reached ≥18mM in diameter. Retrieved gametes were cultured in specific media for conventional in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) and maintained in incubators at 37°C with 5-6% CO₂. During follicular aspiration, 4 mL of follicular fluid (FF) was collected from dominant follicles, with visibly contaminated samples discarded, and 4 mL of venous blood was simultaneously collected using tubes with heparin or EDTA. Samples were centrifuged at 10,000×g for 10 minutes at 4°C to separate plasma and remove cellular debris, with supernatants aliquoted into 500μL portions and stored at -80°C. Reactive nitrogen species (RNS) were quantified by treating samples with acetonitrile (2:1) for protein precipitation, followed by the addition of Griess reagent and absorbance reading at 540 nm. Glutathione levels were determined using the spectrophotometric enzymatic recycling method in samples treated with 10% trichloroacetic acid (TCA). Reduced glutathione (GSH), disulfide glutathione (GSSG), and the GSSG/tGSH ratio were measured. Reactive oxygen species (ROS) were quantified using electron paramagnetic resonance (EPR) after treating samples with CMH (carboxymethoxyhydroxyamine), incubating them at 37°C for 30 minutes before freezing and storage. ART=assisted reproductive technologies; VCl3=vanadium chloride.