Azoospermia

Azoospermia is a condition in which there are no sperm in the semen. Keep in mind, that doesn't mean the total absence of fluid. The ejaculate comes from two sources. The first part, the seminal fluid, is produced by the prostate gland and seminal vesicles. The seminal fluid, which comprises 98% of the volume of the ejaculate, is simply "carrier fluid" which sustains and nourishes the sperm and provides a medium for their journey towards the egg. The other 2% of the ejaculate volume is comprised of the actual sperm cells, which are produced in the testicle, and are designed to swim to the egg and fertilize it. Most men with azoospermia have normal amounts of seminal or "carrier" fluid—only the sperm are absent.

Azoospermia is usually divided up into two types—obstructive azoospermia and spermatogenic failure.

Obstructive Azoospermia

In obstructive azoospermia (OA), the testicles are producing sperm normally, but for one of several possible reasons, the sperm are unable to reach the outside world. The most common cause of OA is congenital absence of the vas deferens. In this condition, the man has actually been born without vas deferens— the tubes which carry the sperm from each testicle to the outside world. 1 to 2 percent of all infertile men are believed to have this condition.

Other causes of OA can include scarring from surgical procedures such as childhood hernia repairs, neurologic impairment of ejaculation, infections of the testicle or epidiymis, and abnormalities of the prostate gland.

Spermatogenic Failure

Spermatogenic failure means that the production of sperm inside the testicles is severely reduced and possibly completely absent. Another term for this is non-obstructive azoospermia or "NOA."

There are many possible causes of NOA. Some of those causes are congenital, meaning that the condition was present at birth. This includes conditions such as genetic abnormalities, hormonal problems and undescended testicles. In other situations, spermatogenic failure or NOA may have an acquired cause such as chemotherapy or radiation treatment for cancer, side effects from other medications or steroids, or environmental exposure to solvents or toxins.

Any man with azoospermia should undergo a thorough evaluation by a urologist specializing in male infertility. Treatment is often possible, and through the use of advanced reproductive therapies such as IVF, fatherhood remains a real possibility for many men with azoospermia.