Sperm count is a measure of the number of sperm per milliliter of semen, though it can also be measured using other units of volume. Sperm count is often evaluated when a couple is trying to conceive a child, as it can help determine a man's ability to successfully fertilize a woman's egg. Men with lower counts may have a decreased ability to impregnate a woman, and some studies indicate that lowered counts are even related to an increased risk of miscarriage in some cases. It is important to keep in mind, however, that many factors in addition to sperm numbers influence the likelihood of conception.
Male fertility tests typically include a test that is referred to as a sperm count analysis. This test is used to evaluate the number of sperm that are present in a certain amount of semen. If a man has fewer than the number of sperm the lab considers normal, he is said to have a low sperm count, which may interfere with his ability to father a child. This does not necessarily mean he cannot ever make a woman pregnant, however. Instead, fertilizing an egg may just prove more difficult.
Generally, a man is considered to have a normal sperm count if he has 20 million sperm per milliliter of semen, but this number alone is not a definitive measurement of a man's fertility. This is due to the fact that the lab must also analyze motility to determine the percentage of the sperm present that are actually moving. If the sperm do not move as they should, they cannot reach an egg and fertilize it. Sperm analysis may also include an evaluation of sperm morphology, which is the shape and size of the sperm. When a man has a high number of abnormally shaped or sized sperm, he may prove less likely to fertilize an egg, and his female partner's risk of miscarriage may be higher.
There are numerous possible causes of a lower-than-normal sperm count. Among them are testicular blockages, infections, exposure of the testicles to extreme heat, and ejaculatory problems. Sometimes tumors or chromosomal defects can cause a lowered count as well, and sexual dysfunction, medications, and hormonal imbalances may also cause issues. Exposure to dangerous pesticides, smoking, high intake of alcohol, and high levels of stress can cause sperm volume problems as well.