How is it used?
A semen analysis is used to determine whether a man might be infertile - unable to get a woman pregnant. The semen analysis has many parts and test a lot of aspects of the semen and sperm. A semen analysis to determine fertility should be performed on a minimum of two samples at least seven days apart over a period of two to three months because some conditions can affect sperm levels.
The semen analysis also can be used to count sperm after a man has a vasectomy. If there are still a lot of sperm present in the semen, the man and his partner will have to take precautions so that his partner will not become pregnant. He will have to return for one or more sperm counts until the sperm are cleared from his sample(s).
When is it ordered?
A semen analysis is recommended if a woman cannot get pregnant and when a physician thinks that the patient might have a fertility problem. At least 10%-20% of married couples experience problems conceiving. Male factors are implicated about 50% of the time. Male infertility has many causes and some of these, such as varicocele (enlargement of the veins draining the testes), can be treated successfully. If male factors are involved, analysis of the semen is necessary to determine the feasibility of using assisted reproductive technology to facilitate pregnancy.
What does the test result mean?
The typical volume of semen collected is around one-half to one teaspoonful (2-6 milliliters) of fluid. Less semen would indicate fewer sperm, which would affect fertility. More semen indicates too much fluid, which would dilute the sperm, also impeding fertility.
Sperm concentration (also called sperm density) is measured in millions of sperm per milliliter of semen. Normal is greater than or equal to 20 million per milliliter (and more than 80 million sperm in one ejaculation). The fewer sperm a sample has, the less chance a man has of getting a woman pregnant. A man who has just had a vasectomy would want to have no sperm in his sample.
Motility is the percentage of moving sperm in a sample. The more slowly moving or immobile sperm in a sample, the less likely it is that a man could get a woman pregnant. The progression of the sperm is rated on a basis from zero (no motion) to 3 or higher for sperm that move in a straight line with good speed. If less than half of the sperm are motile, a stain is used to identify the percentage of dead sperm. This is called a sperm viability test.
Morphology analysis is the study of the size, shape, and appearance of the sperm cells. The analysis evaluates the structure of 200 sperm, and any defects are noted. The more abnormal sperm that are present, the lower the likelihood of fertility.
Is there anything else I should know?
Several factors can affect the sperm count and other semen analysis values. A man may have a lower sperm count if he has physical damage to the testicles, has gone through radiation treatment of his testicles, or has had exposure to certain drugs (such as azathioprine or cimetidine). A man with a higher level of estrogens may have lower sperm counts.
Some of the common causes of male infertility are extremely high fever, failure of the testicles, obstruction of the tubes that carry semen to the penis, and a less than normal amount of sperm in the sample (oligospermia).