Causes in Men

Dysfunctional sperm production

A sperm analysis is required to assess male fertility. Decisive sperm parameters include:

• Total number of sperm
• Sperm motility
• Morphology (“appearance”) of the sperm

If the total number of sperm is reduced, then the result will be defined as: OLIGOZOOSPERMIA
If the total number of motile sperm is reduced: ASTHENOZOOSPERMIA
If the total number of normally shaped sperm is reduced: TERATOZOOSPERMIA If all three parameters are reduced: OAT-Syndrome

Factors that play a role in decreased fertility:

• Undescended testis
• Varicocele (testicular varicose vein)
• Previous mumps infection with testicular involvement
• Hormonal disorders
• Inflammation
• Stress
• Excessive consumption of alcohol and nicotine
• Environmental factors
• Operated tumors, chemotherapy, radiation therapy
• Genetic causes (such as Klinefelter Syndrome)
• Disturbance in sperm transport

In some instances, testicular sperm production may suffice, but an obstruction in the male reproductive system blocks the path of the sperm. This leads to a complete absence of sperm in the ejaculate (azoospermia).

Causes of azoospermia are:

• Closure of the vas deferens due to inflammation
  
• Sterilization (vasectomy)
  
• In rare cases, failure of formation of the vas deferens may be present at birth.