(429) Testosterone Use and Semen Quality in a Large Cohort of Men Seeking Fertility Evaluation

Abstract Introduction Exogenous testosterone use is associated with a decrease in endogenous testosterone production via excess negative feedback on the hypothalamic-pituitary-gonadal excess, which impairs spermatogenesis. While withdrawing exogenous androgen therapy can lead to recovery of spermatogenesis, this may take months to years and sperm counts may not fully recover. Therefore, men interested in fertility should be counseled not to utilize exogenous testosterone either therapeutically or recreationally. Objective Using data collected from the Fellow Health mail-in semen analysis (FSA) system, we sought to analyze the rate of testosterone usage for patients seeking fertility evaluation, associated semen quality, and potential predictors of low total motile count (TMC). Methods Men submitting FSA between August 2020 and May 2025 who consented to participate and completed a detailed sociodemographic and exposures survey were included in this study. Testosterone users were defined as those who indicated testosterone was a current medication when submitting their semen analysis kit. Patients who did not provide data on current medications were excluded, along with those who submitted FSA samples to verify the success of their vasectomy or vasectomy reversal. Patients age, self-reported reason for testing, total motile count (TMC), and three area-level measures derived from their home zip code (urbanization, geographic region, and socioeconomic distress) were collected. Chi-squared tests, t-tests, and multivariate logistic regression results were used and significance was reported at the 0.05 alpha level. Analyses were conducted using R version 4.4.0. Results Of 8,148 men seeking fertility evaluation, 306 (3.8%) reported current testosterone use. The rate of use varied by self-reported reason for fertility testing (p<0.01): it was highest among those indicating they were “just curious” (7.6%), and lowest among those who had been trying to conceive for 7-12 months or 12+ months (both 2.6%). Testosterone users had an average TMC of 24.9M cells compared to 91.4M cells for known non-users (p<0.01) (Table 1). Multivariate logistic regression analysis demonstrated that testosterone users had a 7.31 (95% CI: 5.57-9.73) times greater odds of TMC < 20M than non-users, after adjusting for age, reason for testing, urbanization, and community-level socioeconomic distress (Table 2). Older age (OR X, 95% CI), higher distressed community index (OR, 95% CI), and longer time on fertility journey (OR, 95% CI) were also associated with TMC <20. Conclusions It is well known that testosterone use impairs spermatogenesis. In this large cohort of men seeking fertility evaluation, almost 4% were actively using exogenous testosterone. Men who were further along in their fertility journey were less likely to be using testosterone, suggesting patient understanding of the impact of testosterone on fertility and their responsiveness to impactful educational messages. Disclosure Yes, this is sponsored by industry/sponsor: Fellow Health, Inc Clarification: Industry initiated, executed and funded study Any of the authors act as a consultant, employee or shareholder of an industry for: Fellow