Male infertility can be primary or secondary, depending on whether pregnancy has been achieved before or not, but thyroid gland involvement is rarely investigated in the laboratory work-up. This study aimed to assess thyroid hormone abnormalities among primary and secondary infertile men.

This is a cross-sectional study involving male partners of infertile couples presenting at the fertility clinic with an established diagnosis of infertility after review by the clinician. Males with proven fertility served as controls.

The study was conducted at the Human Reproduction and Research Programme unit and the Chemical Pathology Laboratory of the University of Benin Teaching Hospital, Benin City, Edo State, Nigeria.

This study involved 200 participants who consisted of 50 controls (fertile men) and 150 infertile men (80 primary infertile men and 70 secondary infertile men). The participants were reviewed by a clinician, and a semen analysis was done to ascertain their fertility status.

The results show that sperm indices, such as sperm count, total motility, progressive motility, viable sperm cells, normal forms and volume were significantly lower (p

Thyroid abnormalities were more predominant among secondary infertile men than primary infertile men in this study.