What Causes Male Infertility?

Infertility is a common problem and may affect up to 15% of all couples: it is also on the increase as more people are delaying the start of their families. Infertility had been traditionally thought of as a primarily female problem; urologists now realize that male infertility may also be involved in half of all infertility cases.

What is infertility?

Primary infertility describes couples who have never been able to become pregnant after at least 1 year of unprotected sexual intercourse.

Secondary infertility describes couples who have been pregnant at least once, but have not been able to become pregnant again.

What is male infertility?

Male infertility is any condition in which the man adversely affects the chances of initiating a pregnancy with his female partner. Most commonly, those problems arise when the man is unable to produce or deliver fully-functioning sperm.

What causes male infertility?

The causes of male infertility are numerous, some are simple and easily corrected, and others are more complex and genetic.

Overall, these causes can be divided into two groups: production problems or obstruction.

1. Production problems:

  1. Varicocele: Varicose veins of the testicle or Varicocele are the most common problem. Varicocele is even more common in men who have previously fathered children and are now unable to do so.   It may lead to reduced sperm count and/or motility.
  2. Medication: Certain medications can affect sperm production, function and ejaculation. Such medications are usually prescribed to treat conditions like arthritis, depression, digestive problems, infections, hypertension and even cancer.
  3. Hormones: Hormones produced by the pituitary gland are responsible for stimulating the testicles to make sperm. Therefore, when levels are severely low, (hypogonadism) poor sperm development can result.
  4. Sperm disorders: Problems with the production and development of sperm are the most common problems of male infertility. Sperm may be underdeveloped, abnormally shaped or unable to move properly. Or, normal sperm may be produced in abnormally low numbers (oligospermia) or seemingly not at all (azoospermia).
  5. Smoking: Smoking cigarettes has been linked to impaired morphology and motility of sperm cells
  6. Alcohol: Alcohol may interfere with sperm development and hormone levels

2. Obstruction: Normal sperm production takes three months, the final two and a half weeks of which are spent traveling from the testicle to the outside. The distance over which sperm must travel is 15 to 20 feet, mainly through tiny, microscopic tubules. The tubules may be blocked for the following reasons:

  1. Previous Vasectomy is the most common cause and can be reversed in many cases through a micro-scopic vasectomy reversal procedure.
  2. Retrograde ejaculation: Retrograde ejaculation occurs when semen pushes backwards into the bladder instead of out the penis. This is caused by the failure of nerves and muscles in the bladder neck to close during orgasm. It is one of several difficulties couples may have delivering sperm to the vagina during intercourse. Retrograde ejaculation can be caused by previous surgery, medications or diseases affecting the nervous system. Signs of this condition may include cloudy urine after ejaculation and diminished or “dry” ejaculation with orgasm.
  3. Inflammation, repeated infections or scarring may block the normal passage of sperm at any portion of the male reproductive tract and cause obstruction.

Immunologic infertility: Triggered by a man’s immunologic response to his own sperm, antibodies are usually the product of injury, surgery or infection. In attacking the sperm, they prevent normal movement and function of the sperm. Although researchers do not yet understand just exactly how antibodies damage fertility, they know that these antibodies can make it more difficult for sperm to swim to the uterus and penetrate eggs.

Genetics: Genetics play a central role in fertility, particularly since sperm carry half of the DNA mix to the partner’s egg. Abnormalities in chromosomal numbers and structure as well as deletions on the important Y chromosome present in normal males can also impact fertility.