Semen analysis

Definition

A semen analysis is a test to measure the amount and quality of a man's semen and sperm. It is sometimes called a sperm count.

Alternative Names

Why the Test is Performed

The test is done to evaluate a man's fertility. Approximately half of couples unable to have children have a male infertility problem.

One of the first tests done to evaluate a man's fertility is the semen analysis. It can help determine if a problem in sperm production or quality of the sperm is causing infertility.

The test may also be used after a vasectomy to make sure there are no sperm in the semen. This can confirm the success of the vasectomy.

The test may also be performed for the following condition:

• Klinefelter syndrome

How the Test is Performed

A semen sample will be obtained. Semen is the thick, white, sperm-containing fluid released during ejaculation. Discuss the method of sample collection with your health care provider.

The sample may be obtained by masturbation into a sterile container. It may also be achieved by intercourse using a special condom supplied by the health care provider. The sample must be analyzed within 2 hours of the collection. The earlier the sample is analyzed, the more reliable the results.

At the laboratory, the semen sample is analyzed and the following are determined:

• Fluid coagulation (thickening into a solid) and liquefication
• Fluid thickness, acidity, and sugar content
• Resistance to flow (viscosity)
• Sperm movement or motility
• Number and structure of the sperm
• Volume of semen

How to Prepare for the Test

Do not have any sexual activity that causes ejaculation for 2 - 3 days before the test.

How the Test Will Feel

If you are uncomfortable about how the sample is to be taken, discuss it with your health care provider.

Risks

There are no risks.

Considerations

The use of the following may affect a man's fertility:

• Alcohol
• Many recreational and prescription drugs
• Tobacco

Normal Results

A few of the common normal values are listed below.

• The normal volume varies from 1.5 to 5.0 milliliter per ejaculation.
• The sperm count varies from 20 to 150 million sperm per milliliter.
• At least 60% of the sperm should have a normal shape and show normal forward movement (motility).

However, how to interpret these values and other results from a semen analysis is not completely certain.

Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

What Abnormal Results Mean

Abnormal results may suggest a male infertility problem. For example, if the sperm count is very low or very high there is a likelihood of being less fertile. The acidity of the semen and the presence of white blood cells (suggesting infection) may influence fertility.

However, there are many unknowns in male infertility. The results from the test may fail to explain the cause. If a low sperm count or abnormal semen is found, further testing may be required.