CHICAGO – Levels of thyroid stimulating hormone were significantly higher in women with unexplained infertility than in a cohort whose partners had severe male factor infertility, though TSH levels still fell within the reference range.
For women with unexplained infertility, thyroid stimulating hormone (TSH) averaged 1.95 mIU/mL (95% confidence interval, 1.54-2.61), compared with 1.66 mIU/mL for the group of women with severe male factor infertility, such as severe oligospermia or azoospermia (95% CI, 1.25-2.17; P = .003).
“We found, very interestingly, that in the unexplained group, TSH was higher in those women, compared with women whose partners had severe male factor infertility,” suggesting that , the study’s first author, Lindsay T. Fourman, MD, said in an interview at the annual meeting of the Endocrine Society.
In terms of TSH levels, “clearly, the cutoff of the upper limit of the normal range is controversial,” said Dr. Fourman. “Some studies have shown that 95% of the population has a TSH of less than 2.5.”