Varicocele
A varicocele (var'i-ko-sel') 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. Treating the varicocele, which is 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 treatment with an antibiotic.
Hormonal problems
Sperm production is under the control of special hormones that come both from the pituitary gland (FSH, LH) and from the testicle (testosterone). If the blood levels of these 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 causes were unclear in the past, are actually caused by genetic abnormalities. These include cases in which whole chromosomes are broken, misshapen, or missing, an extra chromosome is present, or 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, are filled with many breaks and nicks. In many instances, this is believed to be due to oxidative stress.
Blockage of sperm flow
Sperm are produced in the testicles and then move out into the epididymis, where they become fully mature. After several days in the epididymis, the sperm swim up a tube called the vas deferens, towards the ejaculatory duct. There are several conditions that 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 steroids and hormones, can have a temporary effect that 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.
