Factors Which Impact Sperm Viability
Low sperm count is the number one issue regarding male infertility. Coming soon after low sperm count is low motility, or sperm which do not move as they should. Finally, there could either be a lack of semen, or sperm which is simply of poor quality, meaning they don't travel in a straight direction, or travel quickly enough to reach the egg in time to successfully fertilize. It is beginning to look as if age may play a significant part in fertility rates, although scientists are not clear on the reason. For men under the age of forty, the percentage of healthy men who have no problems conceiving, is around fifty to sixty percent, however once men pass the forty-mark, the fertility rates falter. A general "laundry list" of lifestyle issues which can affect fertility include the hormonal problems brought on by emotional stress, premature ejaculation, relationship problems or even the use of lubricants. These are generally considered temporary fertility issues, as most of them can be altered or can change naturally.
Other Factors
Overheating from a high fever, sauna or hot tub can lower a man's sperm count, although the effect is generally only temporary, however if a man works at a job where he is continuously exposed to overheating, his fertility may be seriously impaired. Men who use cocaine or are substantial marijuana users seem to have both fewer sperm and sperm of a lower quality. The viable sperm of a man who uses recreational drugs can decrease by as much as half. It appears that marijuana, in particular greatly affects the sperm's ability to make its way toward the egg and find its way inside. Smoking cigarettes can also reduce the lifespan of sperm, lower sperm count and motility, and even alter certain genetics which can adversely affect future offspring. Aside from having a negative impact on fertility, smoking cigarettes also contributes to less-than-stellar sex drives, which, of course results in less frequent sex. A relationship between obesity in men and lower levels of sperm has been found, so men who are trying to conceive should keep their weight within normal levels. Certain vitamin deficiencies-most notably Vitamin C, selenium, zinc and folate-can also contribute to infertility in men.
Genetic Factors
Scientists are finding that genetic factors also play an important part in male infertility. For example, men who have cystic fibrosis may also be lacking the tube which carries the sperm, or it could be obstructed, resulting in lowered fertility. Men who suffer from Klinefelter syndrome will carry two X chromosomes and one Y, while the "norm" is one X and one Y, leaving most male attributes unimpaired, while frequently destroying the lining in the testicles during puberty. Finally, a relatively rare disease which can reverse the position of some major organs in men, thus leading to infertility problems in men is known as Kartagener syndrome.
Other factors in sperm viability in men can include exposure to environmental toxins, or repeated exposure to heavy metals and arsenic which seem to inhibit the enzymes in sperm, rendering men infertile. Men who have had to undergo cancer treatments such as chemotherapy or radiation may also experience lowered sperm viability. While there may be other factors affecting sperm viability and a man's ability to conceive, these are the most common.