Abstract
Abstract
Background
Thyroid dysfunction, particularly hyperthyroidism, is a recognized modulator of female fertility, yet its prevalence among infertile women remains inadequately characterized. This study aimed to determine the prevalence of biochemical hyperthyroidism among infertile women referred to assisted reproductive technology (ART) centers in West Azerbaijan, Iran.
Methods
In this retrospective cross-sectional study, medical records of 712 infertile women (aged 18–45 years) evaluated between 2020 and 2024 were analyzed. Thyroid function was assessed using serum Thyroid-Stimulating Hormone (TSH) and Free Thyroxine (FT4). The primary outcome was the prevalence of overt biochemical hyperthyroidism (TSH
Results
The prevalence of overt hyperthyroidism was 2.8% (95% CI: 1.8–4.2), and subclinical hyperthyroidism was 4.5% (95% CI: 3.2–6.2). Overall, 7.3% of women had suppressed TSH. Women with any suppressed TSH (combined overt and subclinical) were significantly older (33.5 ± 5.1 vs. 31.2 ± 5.8 years,
p
= 0.004) and more frequently had secondary infertility (59.6% vs. 40.5%,
p
= 0.031) compared to euthyroid women. Logistic regression confirmed that older age (aOR = 1.07, 95% CI: 1.02–1.13) and secondary infertility (aOR = 2.12, 95% CI: 1.17–3.84) were independently associated with the combined outcome.
Conclusion
A significant proportion of infertile women had biochemical evidence of thyroid hormone excess, with older age and secondary infertility as key associated factors. These findings may support the benefit of systematic thyroid assessment in women undergoing infertility evaluation.