Hormonal Regulation of Male Fertility

Hormones regulate every aspect of male reproduction, from sperm production to libido. The hypothalamus-pituitary-gonadal (HPG) axis is the key 男性不妊 system involved:

1. Hypothalamus: Releases gonadotropin-releasing hormone (GnRH).
2. Pituitary Gland: Produces luteinizing hormone (LH) and follicle-stimulating hormone (FSH).
   • LH stimulates testosterone production in the testes.
   • FSH is critical for sperm production.
3. Testes: Produce testosterone and sperm.

Effects of Low Testosterone:

1. Reduced Sperm Production:
   • Testosterone is essential for spermatogenesis in the seminiferous tubules. Low levels result in decreased sperm count and quality.
2. Impaired Libido and Sexual Function:
   • Low testosterone leads to reduced sexual desire, which can indirectly affect fertility.
3. Other Hormonal Imbalances:
   • Imbalances in prolactin, estrogen, or thyroid hormones can also disrupt the HPG axis, affecting fertility.

Causes of Hormonal Imbalances:

• Primary Hypogonadism: Testicular failure to produce adequate testosterone due to injury, infection, or congenital issues.
• Secondary Hypogonadism: Dysfunction in the hypothalamus or pituitary gland caused by tumors, medications, or systemic diseases.
• Lifestyle Factors: Stress, obesity, and poor diet can lower testosterone levels.

Diagnosis and Treatment:

• Hormonal assays measure testosterone, FSH, LH, and prolactin levels.
• Treatments include testosterone replacement therapy, medications to stimulate hormone production, or addressing the underlying cause.