Sperm regeneration is the renewal of sperm supplies with fresh spermatozoa ready for fertilization. Men continually produce their gametes throughout their lives, unlike women, who are born with a supply of eggs and do not grow more as they mature. It can take approximately 72 days for a sperm cell to develop and fully mature, although some studies suggest the process may be shorter in some men. In couples with fertility problems, a doctor may evaluate the sperm to determine if the issue lies with some stage of the sperm life cycle.
When men ejaculate, they release sperm and other compounds, some of which are designed to facilitate fertilization. A supply of new sperm cells ready for fertilization moves in to replace the ejaculated cells to continually renew the man's fertility. Sperm regeneration starts in the testes, where sperm cells develop, and transitions to a tube behind the testicles called the epididymis, where the cells acquire motility, the ability to move on their own. The motile cells travel down a duct called the vas deferens to await ejaculation.
Studies on sperm regeneration illustrate the importance of being careful about exposure to environmental toxins while trying for a pregnancy. Anything a man is exposed to in a roughly two month period before attempting to impregnate a partner can affect the quality of his sperm. This can include medications, alcohol, cigarettes, and chemicals a man may be exposed to at work or through a hobby. These can slow the rate of sperm development or increase the chances of chromosomal abnormalities that might cause a problem with a pregnancy.
Fertility doctors and researchers study sperm regeneration to learn more about how quickly a man's supply of sperm renews. They also look at the factors that can impact sperm quantity and quality. Frequent ejaculations, for example, can outstrip the ability to produce new sperm, and may result in a decline of fertility until sperm regeneration catches up. A fertility specialist may have specific advice for a patient on topics like diet and sexual activity to increase the chances of a successful pregnancy.
As men age, the sperm regeneration process can slow and may be more prone to errors. Older men may produce sperm with more chromosomal abnormalities. They can have trouble achieving successful pregnancies, although it is still possible. Changes in sperm quality can onset as early as a man's 30s. Testing in a lab can provide important information about an individual patient's sperm in the event of fertility issues.