Autoimmune Thyroid Disease and Female Fertility: Clinical Evidence on Ovarian Reserve, Infertility Treatment Outcomes, and Pathophysiology.

BACKGROUND

Thyroid autoimmunity (TAI) is prevalent among women of reproductive age and has been associated with impaired fertility; however, its effects on ovarian reserve and infertility treatment outcomes remain controversial.

METHODS

A narrative review was performed using PubMed to identify clinical and experimental studies addressing TAI, ovarian reserve, premature ovarian insufficiency (POI), and infertility treatment outcomes.

RESULTS

Clinical evidence suggests that TAI is associated with modestly reduced AMH levels in adult women, although the magnitude of this decline appears insufficient to indicate imminent POI. In contrast, adolescents with TAI may exhibit elevated AMH. Observational studies describe a frequent coexistence of TAI and POI; however, Mendelian randomization analyses suggest that POI may predispose to TAI rather than the reverse. Mechanistic studies show that thyroid hormones act directly on ovarian cells via thyroid hormone receptors, while immune-mediated pathways involving cytokines, oxidative stress, and anti-ovarian antibodies may contribute to follicular dysfunction. Evidence regarding assisted reproductive technology outcomes in euthyroid TAI remains inconsistent.

CONCLUSION

TAI may exert a subtle influence on ovarian reserve through complex endocrine and immune mechanisms, with age-specific variation. Although AMH alterations are observed, their clinical relevance for fertility and treatment outcomes remains unclear, highlighting the need for longitudinal studies.