What Causes Male Infertility?

When it comes to determining the cause of male infertility, it is essential to be seen by a male infertility specialist like Dr. David Fenig. Most reproductive endocrinologists at IVF centers focus on female fertility issues and often lack the specialty training to comprehensively evaluate and treat the cause of male problems, and counsel patients accordingly.  Dr. Fenig is one of only a few male infertility experts to have received specialty training in helping couples conceive in as natural way as possible.

Causes of Male Infertility

Male infertility is most commonly caused by problems with the production and maturation of sperm, which can be immature, abnormally shaped, or unable to “swim” properly. Sometimes normal sperm is produced in abnormally low numbers (oligospermia) or seemingly not at all (azoospermia).

This can result from many different conditions, including:

  • Varicoceles 
  • A vasectomy, in which case Dr. Fenig can perform a microsurgical vasectomy reversal
  • Undescended testicles or prior testicular surgery
  • Trauma to the testis
  • Infections of the testicle and chronic inflammatory conditions
  • Endocrine or hormonal disorders like low testosterone
  • Lifestyle factors and environmental exposures such as pesticides, chemical solvents or radiation
  • Genetic diseases or chromosomal abnormalities including cystic fibrosis
  • Testosterone or steroid use


Understanding Oligospermia and Azoospermia

Male Infertility issues are often the result of oligospermia, low levels of sperm that can be caused by genetic, structural, hormonal or environmental factors, as well as excessive drug, alcohol and tobacco use. It is common for men to experience low sperm count due to a varicocele or even a hormonal imbalance like low testosterone.

Approximately five to 20% of men with infertility suffer from a complete lack of measurable sperm in their semen, a condition known as azoospermia.

  • Non-obstructive azoospermia is caused by a sperm production problem. Chemotherapy, radiation, and certain medications including hormones or steroids, can all cause azoospermia. Chronic illness, fevers, heat exposure and past injuries to the scrotal area are also assessed by Dr. Fenig as potential factors. A family history can also provide important clues about possible genetic issues.
  • Obstructive azoospermia is caused by a blockage of the vas deferens or epididymis. The most common cause of obstructive azoospermia is prior vasectomy.  Infections of the epididymis, the crescent-shaped gland around the testis responsible for sperm maturation and storage, may cause scarring, preventing the sperm from reaching semen in high enough numbers to fertilize an egg.  Fortunately, Dr. Fenig’s success rate for repairing blockages using microsurgery is high in appropriately selected patients. 


Dr. Fenig will perform a comprehensive physical exam and evaluation to determine the exact cause of your infertility. Learn more about diagnosis here.