WHAT ARE THE CAUSES OF MALE INFERTILITY?

When the semen analyses are abnormal, the urologist's evaluation may reveal the source of the problem. The possible causes include:

• Varicocele

  A varicocele (var-i-co-seal) is a condition in which the veins surrounding the testicle become swollen and dilated. It is fairly common, affecting about one in every seven men. Men with a varicocele have about a 50% chance of having an abnormal sperm count. Varicoceles are believed to harm sperm production by causing increased oxidative stress in the testicular tissue. Oxidative stress is a condition in which increased levels of harmful molecules known as "free radicals" can damage the sperm forming tissue. Treating the varicocele, usually done with a minor surgical procedure, will often correct the problem.

• Infection

  Infections of the prostate or epididymis (a duct behind the testicle) can have a major impact on a man's fertility. Such an infection would usually be diagnosed by the finding of numerous white blood cells in the semen. If infection is suspected, the urologist may request a semen culture, and being treatment with an antibiotic.

• Hormonal problems

  Sperm production is under the control of special hormones which come both from the pituitary gland (FSH, LH) and from the testicle (testosterone). If the blood levels of those hormones are abnormal, sperm production may be very low, or even completely absent. This type of problem is diagnosed with simple blood tests, and, if present, may be correctable with medication.

• Genetic abnormalities

  We now realize that many cases of male infertility whose cause was unclear in the past are actually caused by genetic abnormalities. This includes problems in which whole chromosomes are broken or misshapen, where a whole chromosome is either missing or an extra one is present, and instances where individual genes on the Y- chromosome are damaged. Another type of genetic problem is known as sperm DNA fragmentation. In this condition, the DNA strands which contain the genetic information in the sperm head are filled with many breaks and nicks. This is believed to be due, in many instances, to oxidative stress (see below).

• Blockage of sperm flow

  Sperm are produced in the testicles. They then move out into the epididymis, a small duct behind the testicle, where they become fully mature. After several days in the epididymis, they swim up a tube called the vas deferens towards the ejaculatory duct. There are several conditions which can lead to a blockage of the path from testicle to ejaculatory duct. Such a blockage could cause the sperm count to be extremely low, or even create a condition known as azoospermia, in which no sperm are present in the ejaculate at all. Sometimes, a blockage can be repaired. And even if repair of the blockage is not possible, a pregnancy should be achievable through IVF.

• Medication and treatment side effects

  Certain medications or medical treatments can interfere with sperm production. Radiation treatment for cancer can impair testicular function. Many chemotherapy drugs will have a permanent effect on production. Some drugs, such as testosterone replacement therapy, can have a temporary effect which should reverse when the medication is stopped. When taking a medical history, the urologist will ask about any medications or illnesses that have occurred in the past.