Causes of Male Infertility

Sperm Health & Production

Some issues with sperm health and production can start from birth or childhood. For example, if you have contracted mumps or have struggled with testicle development, sperm production may be affected. Hormone imbalances, infections, other medical issues, age, and long-term illness can cause poor sperm health. Sperm development and health can also be affected by lifestyle issues like smoking, drinking alcohol, and obesity.

The most common problems around poor sperm health and function include:

• Sperm don’t fully develop
• Abnormal shape or size (sperm morphology)
• Not moving properly (sperm motility)
• Not enough sperm being produced (low sperm count, or oligospermia)
• No sperm being produced (azoospermia)

Obstructions in the Male Reproductive System

A common cause of male infertility is swollen veins in the scrotum, called a varicocele. Swollen veins block blood drainage from the scrotum, which harms sperm. Sometimes, varicoceles force blood to flow back into the scrotum, which warms the testicles too much, thereby decreasing sperm production.

Other blockages in a man’s reproductive tract can be caused by:

• Repeat infections
• Surgery, such as vasectomy
• Developmental defects from childhood

When blockage occurs, sperm cannot combine with the seminal fluid, or the semen can’t exit the penis during ejaculation.

Chromosome Defects

Chromosomes carry the DNA molecules that make a person. Abnormalities in the shape or number of chromosomes can affect conception or cause genetic birth defects in a baby, such as Down syndrome or heart defects. A man can also inherit chromosome disorders that cause infertility, including cystic fibrosis, Klinefelter’s syndrome, and Kallmann’s syndrome.

A male partner may be a candidate for preconception genetic counseling based on family history, especially if it includes heart disease or sickle cell disease. Some conditions in the family line could be a cause for male infertility or can lead to recurrent miscarriage, infant death, or birth defects in a child.

Genetic Carrier Screening

Certain Medications

Certain medications can alter sperm production, function, and delivery. It’s worth asking our fertility specialists whether certain medications for arthritis, depression, infections, ulcers, psoriasis, high blood pressure, and cancer could affect fertility.

Men who are treated for low-T (low testosterone) with hormone replacement therapy may experience reduced or halted sperm production. In effect, low-T treatments serve as a kind of male birth control. Long-term use of testosterone replacement may even cause sterility.

The use of anabolic-androgenic steroids, derivatives of testosterone often used to build strength and muscle mass, has proven to cause infertility in men, as well. Abuse of these steroids is linked to low or no sperm count as well as abnormalities in sperm movement and shape.

Weight and Lifestyle

A number of studies show that obesity contributes to male infertility. The extraneous fat on a man’s body produces a hormone that decreases sperm count, production, and quality. In fact, the odds of infertility increase by 10% for every 20 pounds that a man is overweight.¹

Obesity is just one lifestyle factor that affects male infertility. Smoking cigarettes, drinking alcohol, using recreational and illegal drugs, psychological or emotional stress, and caffeine consumption can all play a role. Prolonged exposure to heat on the testicles can also impact sperm production for example frequent exercise in restrictive clothing such as cycling, prolonged hot tubs or sauna use or even frequent use of a hot laptop sitting on your lap.

Though not a lifestyle factor a man can change, advanced age can also contribute to a reduction in a man’s fertility.

Other Causes of Male Infertility

Male infertility can also be caused by the following:

• Hormone imbalances
• Medical conditions like diabetes and cancer
• Erectile dysfunction

To determine the potential cause of infertility, our specialists will need to perform a series of tests to evaluate you and your partner. We can then recommend the best treatment to help you achieve your family-growing goals.

Testing for Men