A prospective cohort study of somatic and reproductive manifestations of thyroid dysfunction in women of reproductive age

Infertility remains a major medical, social, and demographic challenge worldwide. According to the World Health Organization, 15–17 % of couples of reproductive age experience difficulty conceiving, with female infertility accounting for more than 40 % of cases. Endocrine disorders, particularly thyroid dysfunction, play a significant role in the structure of female infertility due to their impact on the hypothalamic–pituitary–ovarian axis, ovulation, and endometrial receptivity. Aim. To assess the effect of thyroid dysfunction on reproductive capacity in women of reproductive age in a prospective cohort study. Materials and methods. A prospective cohort study was conducted at the Department of Reproductive Medicine and Clinical Embryology, Shupyk National Healthcare University of Ukraine, between 2024 and 2026. The study included 245 women of reproductive age presenting with impaired reproductive function. All patients underwent comprehensive clinical, laboratory, and instrumental assessment, including evaluation of thyroid function (thyroid-stimulating hormone (TSH), free thyroxine (fT4), thyroid autoantibodies) and thyroid ultrasound. Reproductive parameters were assessed dynamically during follow-up. Results. Women with thyroid disorders demonstrated a markedly higher incidence of menstrual irregularities, anovulation, and reduced fertility compared to those without thyroid dysfunction. Both overt and subclinical hypo- and hyperthyroidism were associated with adverse reproductive outcomes, including decreased pregnancy rates and increased risk of pregnancy loss. Follow-up indicated statistically significant improvement in reproductive outcomes following normalization of thyroid function. Conclusions. Thyroid dysfunction is a significant factor contributing to impaired female reproductive potential. Correction of thyroid dysfunction was associated with significant improvement in reproductive outcomes, supporting targeted early diagnosis and management of thyroid disorders as an essential component of infertility care.