Concomitant intramuscular human chorionic gonadotropin preserves spermatogenesis in men undergoing testosterone replacement therapy

This retrospective study from Baylor College of Medicine addressed a frequent clinical problem: suppression of spermatogenesis induced by testosterone replacement therapy (TRT). Exogenous testosterone suppresses the hypothalamic-pituitary-gonadal axis via negative feedback, reducing LH and FSH and consequently sperm production — an effect that can lead to azoospermia in up to 40% of men on TRT.

The researchers evaluated men who received hCG 500 IU every other day concomitantly with TRT. hCG, by mimicking LH action, directly stimulates Leydig cells to produce intratesticular testosterone, maintaining the hormonal environment necessary for spermatogenesis in Sertoli cells.

The results demonstrated that hCG co-administration was able to:

• Preserve spermatogenesis in the majority of treated patients
• Maintain adequate intratesticular testosterone levels, essential for sperm maturation
• Preserve seminal parameters such as sperm concentration and motility
• Maintain the clinical benefits of TRT without compromising fertility

This study was clinically relevant for offering a practical solution for men of reproductive age who require TRT but wish to preserve fertility. The addition of hCG to TRT subsequently became a widely adopted practice in andrology and male reproductive medicine clinics, representing a paradigm that the benefits of TRT can be obtained without the cost of infertility.