Evaluation of ovarian reserve in women with thyroid autoimmunity

OBJECTIVE: To compare the ovarian reserve of women of reproductive age with and without thyroid autoimmunity (TAI). METHODS: We performed a retrospective analysis of medical records from an assisted reproduction clinic from February 2017 to December 2021. Women aged between18 and 47 years with data on antithyroperoxidase and antithyroglobulin (anti-Tg) antibodies and assessment of ovarian reserve by anti-müllerian hormone (AMH) and antral follicle count (AFC) were included. Among the 188 participants included, 63 were diagnosed with TAI, and 125 had both antibodies negative. AMH and AFC were compared between groups. Subanalysis based on age, types of antibodies, and thyroid function markers were performed. In addition, bivariate analysis and regression models were used. RESULTS: Overall, there was no difference in the median levels of AMH or AFC between the two groups. However, in the subgroup analysis by age, we observed a trend towards lower median levels of AMH in women over 39 years with TAI (0.9 ng/mL vs. 1.5 ng/mL, p=0.08). In a subanalysis according to antibodies, we found a significantly lower median AFC in the group with anti-Tg than in the group without this antibody (8.0 follicles vs. 11.5 follicles, p=0.036). We also found a significantly higher prevalence of anti-Tg in patients with low ovarian reserve compared to those with normal reserve (60.7% vs. 39.3%, p=0.038). CONCLUSIONS: The ovarian reserve of women with TAI appears to be insidiously compromised over the years, with a decreased ovarian reserve in women with anti-Tg.