What causes infertility in men?

What causes infertility in men?

Infertility in men can be caused by different factors and is typically evaluated by a semen analysis. When a semen analysis is performed, the number of sperm (concentration), motility (movement), and morphology (shape) are assessed by a specialist. A slightly abnormal semen analysis does not mean that a man is necessarily infertile. Instead, a semen analysis helps determine if and how male factors are contributing to infertility.

Disruption of testicular or ejaculatory function

• Varicoceles, a condition in which the veins on a man’s testicles are large and cause them to overheat. The heat may affect the number or shape of the sperm.
• Trauma to the testes may affect sperm production and result in lower number of sperm.
• Unhealthy habits such as heavy alcohol use, smoking, anabolic steroid use, and illicit drug use.
• Use of certain medications and supplements.
• Cancer treatment involving the use of certain types of chemotherapy, radiation, or surgery to remove one or both testicles
• Medical conditions such as diabetes, cystic fibrosis, certain types of autoimmune disorders, and certain types of infections may cause testicular failure.

Hormonal disorders

• Improper function of the hypothalamus or pituitary glands. The hypothalamus and pituitary glands in the brain produce hormones that maintain normal testicular function. Production of too much prolactin, a hormone made by the pituitary gland (often due to the presence of a benign pituitary gland tumor), or other conditions that damage or impair the function of the hypothalamus or the pituitary gland may result in low or no sperm production.
• These conditions may include benign and malignant (cancerous) pituitary tumors, congenital adrenal hyperplasia, exposure to too much estrogen, exposure to too much testosterone, Cushing’s syndrome, and chronic use of medications called glucocorticoids.

Genetic disorders

• Genetic conditions such as a Klinefelter’s syndrome, Y-chromosome microdeletion, myotonic dystrophy, and other, less common genetic disorders may cause no sperm to be produced, or low numbers of sperm to be produced.

The most common cause of female infertility is ovulatory problems which generally manifest themselves by sparse or absent menstrual periods.