Semen Analysis

A semen analysis measures the quantity and quality of both the liquid portion, called semen, and the microscopic, moving cells, called sperm.

Semen is the turbid, whitish substance that is released from the penis during ejaculation. Sperm are the cells in semen with a head and a tail that enables them to travel to the egg. A sperm contains one copy of each chromosome (all of the male’s genes) and fuses with the female’s egg, resulting in fertilization.

A typical semen analysis measures:

• the volume of semen,
• the semen consistency (thickness),
• sperm concentration,
• total number of sperm,
• sperm motility (percent able to move as well as how vigorously and straight the sperm move),
• the number of normal and not normal (defective) sperm,
• coagulation and liquefaction,
• fructose (a sugar in semen),
• pH (acidity),
• the number of immature sperm, and
• the number of white blood cells (cells that indicate infection).

Additional tests may be performed if semen is abnormal, such as a test for sperm antibodies. If assisted reproductive technology is contemplated (for example, in vitro fertilization), sperm function tests may also be performed. Sometimes a test called cryosurvival is done to see how well semen will survive for long-term storage, if a couple would like to store sperm for future pregnancies.

Most labs require samples to be collected on-site as the semen needs to be examined within one hour after ejaculation. Semen is collected in a private area, usually a bathroom. The man masturbates and collects the semen in a jar. Some men, for religious or other reasons, might want to collect semen during the act of intercourse, using a condom. If this is the case, the doctor should provide the condom or sheath because lubricated condoms can affect test results. Sperm are very temperature-sensitive. If collection is done at home, the sample should be kept at room temperature (70°F/21°C) at all times. Never refrigerate the sample or try to warm it to body temperature.

To give sperm a chance to replenish, a man should abstain from ejaculating for two to four days before the sample is collected. Follow the instructions that are provided to you.