A Comprehensive Review of Thyroid Dysfunction: Hidden Player in Male Infertility

Abstract

BACKGROUND: Male infertility is a global health challenge and the prevalence is increasing, particularly in the so-called infertility belt of sub-Saharan Africa, including Nigeria. The etiologies are complex and multifactorial. The impact of thyroid disorders on male reproductive health is often overlooked. This unrecognized link can significantly affect sperm quality, quantity, and overall fertility. The involvement of thyroid dysfunction in male infertility is now increasingly reported, but thyroid hormone evaluation is rarely determined in the laboratory work-up during fertility evaluations. The aim of this review is to highlight the involvement of thyroid hormones in the regulation of reproductive function, how thyroid dysfunction induces male infertility, diagnosis, and future directions for research in thyroid-associated male infertility. METHODS: Scientific information reviewed for this purpose was obtained from Google Scholar, PubMed, Web of Science, and other search engines. RESULTS: Studies have indicated that thyroid dysfunction in male infertility is critical to spermatogenesis. Any disruption in the interaction between thyroid hormones and the hypothalamic–pituitary–gonadal (HPG) axis may lead to alterations of the fine hormonal balance needed for optimal reproduction and a spectrum of endocrinopathies. Thyroid dysfunctions have an adverse impact on fertility and male reproductive organs. CONCLUSION: The need to focus on how specific thyroid-related interventions will improve semen quality and if routine thyroid hormone evaluations be included in the diagnostic workup for male infertility are discussed.