A semen analysis measures the quantity and quality of the fluid released from the penis during ejaculation. It evaluates both the liquid portion, called semen, and the microscopic moving cells, called spermatozoa (sperm).
Semen is the turbid, whitish liquid that contains sperm and the products from several glands. It is normally fairly thick after ejaculation and then becomes thinner within ten to thirty minutes. Sperm are the reproductive cells in semen that have a head and a tail. Each sperm contains one copy of each chromosome (all of the male’s genes). Sperm should be progressively motile (can move forward independently) and this allows them to travel to and fuse with the female’s egg, resulting in fertilisation. In each semen sample, there should be millions of sperm and varying amounts of other substances that support fertilisation.
A typical semen analysis could measures:
- Volume of semen
- Consistency (thickness) of the semen
- Sperm concentration
- Total number of sperm
- Sperm motility (the percentage that are able to move, as well as how vigorously and progressively the sperm move)
- Number of normal-shaped and not normal-shaped (defective) sperm
- Coagulation and liquefaction
- Fructose (a sugar in semen)
- pH (acidity)
- Number of immature sperm
- Number of white blood cells (cells that indicate infection)
Additional tests may be performed if semen is abnormal, such as a test for antisperm antibodies. If assisted reproductive technology is contemplated, e.g. in vitro fertilisation (IVF), sperm function tests may also be performed.
How is the sample collected for testing?
Most laboratories require samples to be collected at the hospital as the semen needs to be examined within one hour after ejaculation for a fertility semen analysis. Semen is collected in a dedicated private area with a locked door. The man masturbates and collects the semen in a sterile specimen container.
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 man should ask doctor to provide a silastic condom which is specifically made to be non-toxic to sperm. Do not use standard condoms as these are usually spermicidal.
Sperm are very temperature sensitive. If the sample is collected at home, the sample should be kept next to the body during transportation. It should not be left at room temperature and should not be refrigerated or heated. The sample must be delivered to the lab within one hour for analysis.
Is any test preparation needed to ensure the quality of the sample?
In order for the test to be reliable, you need to abstain from masturbation or sex for two to seven days before the sample is collected. You should follow the instructions given to you by the laboratory or your doctor. You should not collect the sample via intercourse or oral stimulation, as this can contaminate the sample. The penis and genitals should be thoroughly cleaned, rinsed and dried before sample production. No lubricants should be used, as these can be toxic to sperm.