Aspermia

Aspermia, put plainly, describes the condition where there are no sperm present in the male semen. In fertile males with a completely functional reproductive system, the testes constantly produce sperm. Sperm cells are collected in the epididymus (a small sac connected to each testicle) and stored there until a later time when the male reaches orgasm and ejaculates. During the process of ejaculation, a thick, highly concentrated mass of sperm cells (approximately 100 million cells) from the epididymus travels through the vas deferens, a tubular passageway connecting the testicles to the prostate gland. In the prostate gland, sperm are mixed with a more fluid secretion from the prostate gland, seminal vesicles, and Cowper's gland, resulting in the ivory colored fluid (semen) that is released from the penis during ejaculation.

The function of the sperm cells is to provide male germ cells capable of fertilizing an egg. By far, the vast majority of cells present in semen are sperm cells from the testicles. The function of the glandular fluid is to provide a medium for transporting the sperm and an ideal environment in which the sperm cells can swim toward the egg.

From birth through early childhood, the testes naturally do not produce sperm. After the onset of puberty during adolescence, the sperm-producing cells of the testes normally become active, and remain active throughout most of adulthood.

Two common causes of aspermia in males are mechanical obstruction (usually in the vas deferens) and lack of sperm production in the testes. When the passageway between the testes and prostate gland is in some way disrupted, the testes may continue to produce sperm, but there is no physical means for the sperm to mix with glandular fluids and enter the ejaculate. Males may have natural obstructions or be born without a functional passageway joining the testes and the prostate gland. The vas deferens may intentionally be cut surgically in a procedure called a vasectomy as a means of birth control. Some mechanical forms of aspermia can be corrected surgically, and vasectomy is often reversible. In some males, sperm production never begins, or it may cease after a relatively short period of time.

The result of aspermia is that the semen does not contain any significant amount of cellular material and is therefore incapable of causing fertilization of an egg. Since the ejaculate in males with aspermia is not cellular, there is also very little DNA present that might be used in forensic testing. Males with aspermia are generally able to reach orgasm and ejaculate, however, and are typically, therefore, sexually active.

At autopsy, aspermia may provide clues to death caused by prolonged exposure to some toxins, such as thallium, which was used in rodenticides (rat poisons) before being banned. Also, aspermia identified in seminal fluids may help to exclude individuals in paternity issues, and can sometimes provide preliminary information about possible assailants in cases of rape.