A semen analysis is performed when a physician thinks that a person or couple might have a fertility problem.
At least 10% – 20% of married couples experience problems conceiving. Male factors are implicated about 30% of the time and combined male and female factors about 20% of the time. Male infertility has many causes and some of these, such as enlargement of the veins draining the testes (varicocele), can be treated successfully. If male factors are involved, analysis of the semen is necessary to determine what is inhibiting fertility and, when indicated, to evaluate the feasibility of using assisted reproductive technology to facilitate pregnancy. When a semen analysis is abnormal, then the test is repeated at intervals determined by the doctor.
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 tests 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 the sperm count and semen consistency will vary from day to day and some conditions can temporarily affect sperm levels.
The semen analysis also can be used to count sperm after a man has a vasectomy. If there are still sperm present in the semen, whether alive and still motile or apparently dead, the man and his partner will have to take precautions so that the woman does not become pregnant. He will have to return for one or more sperm counts until sperm are no longer present in his sample(s).
When is it ordered?
A semen analysis is typically ordered following a vasectomy and repeated as necessary until sperm are no longer present in the semen sample.
What does the test result mean?
The typical volume of semen collected is around one-half to one teaspoonful (2-6 millilitres) of fluid. Less semen would indicate fewer total sperm, which may affect fertility. More semen indicates too much fluid, which may dilute the concentration of sperm. The semen should initially be thick and then liquefy within 10 to 30 minutes. If this does not occur, then it may impede sperm movement.
Sperm concentration (also called sperm density) is measured in millions of sperm per millilitre (ml) of semen. Normal is 20 million or more sperm per ml, with a total of 80 million or more sperm in one ejaculation. Fewer sperm and/or a lower sperm concentration may impair fertility. Following a vasectomy, the goal is to have no sperm detected in the semen sample.