Ovarian Reserve and Anti-Thyroid Peroxidase Antibodies in Euthyroid Infertile Women: A Cross-Sectional Study.

Objective: This study investigated the association between Anti-TPO levels and ovarian reserve markers, including anti-Müllerian hormone (AMH) and antral follicle count (AFC), in euthyroid infertile women. Materials and methods: In this cross-sectional analytical study, 231 euthyroid infertile women were enrolled and classified as Anti-TPO positive (n = 92) or Anti-TPO negative (n = 139). Serum levels of AMH, FSH, LH, TSH, prolactin, and Anti-TPO were measured, and AFC was assessed by transvaginal ultrasonography. Because hormonal variables were not normally distributed, logarithmic transformation was applied prior to parametric analyses. Data were analyzed using independent t-tests, Pearson correlation, and multivariate regression (α = 0.05). Results: No significant differences were observed between groups in log-transformed AMH, AFC, FSH, or LH levels (p > 0.05). Age was negatively associated with log-AMH. Subgroup analyses demonstrated that in Anti-TPO-positive women, higher Anti-TPO levels were associated with lower log-AMH and higher log-FSH. Multivariate regression identified age as the only independent predictor of log-AMH levels (β = -0.337, p < 0.001). Conclusion: Ovarian reserve decline appears primarily age-related; however, thyroid autoimmunity may have a potential modulatory role in ovarian function. Consideration of thyroid autoantibody status may be clinically relevant in infertility evaluation.