The Correlation Between Male Virility, Reproductive Capacity, and Serum Testosterone Levels: A Semen Morphology and Endocrine Study

Abstract

Male hypogonadism and semen abnormalities are two predominant parameters in male factor infertility. This retrospective cross-sectional study aimed at exploring the role of serum testosterone concentration (total and calculated free testosterone) in the establishment of a connection between sperm morphological integrity, evaluated by Kruger’s strict criteria, and ability to fertilize, focusing on sperm head defects and related cell mechanisms. The electronic patient files of 436 men with infertility were used. In the period between 2019 and 2023, the patients enrolled in the assisted reproductive department of a tertiary hospital underwent examination for hormones and semen quality in accordance with the requirements set by the World Health Organization. Application of Kruger’s strict criteria for morphological classification was undertaken. In the conditions of logistical regression analysis, potential confounding factors, including age, BMI, smoking, and varicocele were also co-evaluated. There was found positive correlation between serum testosterone concentrations, particularly calculated free testosterone, and the percentage of morphologically sound spermatozoa. It was noted that serum testosterone concentrations have a downward trend along with the raising age of men while jokey frequencies of teratozoospermia keep increasing (up to 68.1% in men aged ≥43 years). Sperm head malformation was found to be the main defect type.