Overview

The most common cause of male infertility is low sperm count. Absence of sperm in the semen is less common, affecting 1 out of 100 men and affecting 10 to 15 out of 100 infertile men.

Causes of sperm count problems include:

• Hormonal problems in the testicles or pituitary gland. The pituitary gland releases hormones that stimulate the testicles to produce testosterone.
• Testicular injury or failure, either present at birth (congenital) or associated with radiation or toxic chemical exposure.
• Cancer treatment with certain kinds of chemotherapy or radiation.
• Antibodies that attack sperm and that also may be present in semen. Sperm antibodies sometimes develop when a man's sperm has been exposed to his immune system (outside of the testicles). This may happen after a vasectomy, an infection, or an injury to the testicles.
• Drug use (some prescription medicines, and cannabis [marijuana] and tobacco use).
• Structural problems. These include:
  • A varicocele in the testicles.
  • Blocked ejaculation due to a surgical vasectomy.
  • Absence of a vas deferens (a birth defect that may be associated with the cystic fibrosis genes).
  • Retrograde ejaculation (the ejaculation of semen into the bladder rather than out through the penis).
• Chromosomal problems (such as Klinefelter syndrome).
• Genetic problems.

See a picture of the male reproductive system (Figure 1).

Figure 1 - Male reproductive system

The male reproductive system consists of the penis, two testicles, two epididymides, two vas deferens tubes, two seminal vesicles, and the prostate gland.

Current as of: April 30, 2024

Author: Ignite Healthwise, LLC Staff
Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.