Thyroid-stimulating hormone levels are associated with estradiol levels and impact reproductive outcomes in preconceptionally euthyroid women undergoing their first IVF/ICSI cycles.

Serum TSH levels change significantly during COH and are associated with significant changes in estradiol levels. However, euthyroid women with high-normal TSH levels showed similar development potential for inseminated embryos and early reproductive outcomes compared to those with low TSH levels.