Semen analysis is also called a sperm test.
For this test a sample of semen is required. This is usually produced by masturbation into a sterile pot. Special semen collection condoms (available from the clinic) can also be used for collecting a sample. Normal condoms should not be used as they contain chemicals to kill sperm. Semen is the fluid ejaculated from the penis when a man has an orgasm. It normally contains both fluid (semen) and sperm. The semen needs to be analysed in the laboratory within one hour of production, otherwise the sperm will begin to die. A sperm test will make sure that sperm are present and will provide details on the swimming ability and structure of the sperm.
Sperm tests should be done in specialised laboratories that contain trained staff using the correct equipment. We will require you to undertake a sperm test in one of our accredited fertility laboratories, as other laboratories cannot provide a complete and accurate assessment. We use the WHO 2010 guidelines to grade the results of the sperm tests as normal or abnormal.
A semen analysis reports on
- the volume of semen ejaculated. The volume should be between 1.5-6mls. Low volumes are associated with infertility, while high volumes are seen when there are problems with the prostate gland or seminal vesicles.
- the colour and consistency of the semen. Semen that is very thick (viscous) will often result in lower pregnancy rates. Sometimes many white cells can be seen, suggesting an infection.
- time to liquefy of the semen. The ejaculated semen is thick, and will turn into a liquid within 10-30 minutes of being produced. If the semen does not liquefy, then the sperm will have difficulty in swimming into the womb.
- Number of sperm. Both the total number of sperm in the ejaculate, and the concentration of sperm (ie number of sperms per ml of semen) are reported. The lower the numbers of sperm the lower the chance of pregnancy occurring naturally. When no sperm are seen, despite detailed searching, this is called azoospermia. A normal sperm concentration is 20 million sperm/ml of semen or more.
- the sperm’s ability to swim (motility). The sperm test result will give you the percentages of sperm that cannot swim, those that can swim around in circles but not move forwards, and those that can move forwards. At least 50% of the sperm should be able to swim in a fast forward direction. When the sperm cannot swim well, fertility rates are low.
- Morphology or the normal appearing structure and size of sperm is important for healthy sperm to get inside the egg. Specialised miscroscopes are needed to assess this properly. Sperm abnormalities can be seen in the head, mid-piece or tail of the sperm. A large proportion of human sperm are abnormal and a normal result is that 5% or more of the sperm should have normal morphology
- Sperm antibody testing. This test is performed on sperm to see if they have higher than normal levels of small molecules called antibodies that might block the sperm from being able to get inside an egg.
A blood test to look for genetic causes of sperm problems is also available. This blood test, called a “male reproductive genetic profile” currently reveals a genetic cause for around 5% (1 in 20) men with very low numbers of sperm or absent sperm production. It is believed by researchers around the world that as science discovers more and more about our genetic make-up, a higher proportion of sperm problems will be found to have a genetic cause.