Modulatory Effects of Antioxidant Supplementation on Serum Oxidative Stress Biomarkers MDA and T-AOC in Females with Unexplained Infertility

Unexplained infertility (UI) continues to pose a diagnostic challenge, affecting a considerable proportion of reproductive-aged women. Increasing evidence suggests that oxidative stress (OS) may contribute to impaired female reproductive function. Malondialdehyde (MDA) is a lipid peroxidation marker, while total antioxidant capacity (T-AOC) reflects overall antioxidant defense. Evaluating these biomarkers may help to better understand the role of OS in UI and the potential benefit of antioxidant therapy. A prospective observational study included 30 women diagnosed with primary unexplained infertility. Serum levels of MDA and T-AOC were measured at baseline and after a period of antioxidant supplementation lasting 1-7 months (duration mode: 3 months). All participants received standardized antioxidant therapy consisting of vitamin E (50 mg/day), zinc (15 mg/day), coenzyme Q10 (15 mg/day), and selenium (70 µg/day). Participants with known causes of infertility were excluded. Nonparametric statistical tests were used to evaluate changes in oxidative stress markers before and after supplementation and to compare subgroups with and without comorbidities. Median baseline MDA concentration was 228.2 ng/mL and decreased significantly after antioxidant supplementation to 173.9 ng/mL (p < 0.001), with a reduction observed in 90% of participants. Median T-AOC increased slightly from 23.9 U/mL to 26.2 U/mL, but the change was not statistically significant (p = 0.735). No significant differences in oxidative stress markers were found between women with and without comorbidities, although higher baseline MDA levels were observed in participants with endometriosis (stage I-II). A significant decrease in MDA after supplementation was seen both in women with endometriosis (p = 0.005) and without it (p < 0.001). Women with unexplained infertility demonstrate biochemical evidence of oxidative stress, reflected by elevated MDA levels. Antioxidant supplementation was associated with a significant reduction in lipid peroxidation, suggesting a potential therapeutic role of antioxidants in UI. Combined assessment of MDA and T-AOC may provide useful insight into oxidative imbalance in infertility, although larger controlled studies are needed.