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Semen Analysis
A semen analysis examines a semen sample to assess the number, movement and shape of sperm, used mainly in fertility investigations.
Quick answer
Semen Analysis: what it is and what the results mean
A semen analysis measures several features of a semen sample, including sperm count (concentration), how well the sperm move (motility) and their shape (morphology), along with the volume of the sample.
- Why it is done: It is used to investigate fertility problems in couples trying to conceive, to check the success of a vasectomy, and sometimes to assess the effects of treatment or conditions affecting sperm.
- Understanding results: Results are compared with reference values for count, motility and shape.
What it is
A semen analysis measures several features of a semen sample, including sperm count (concentration), how well the sperm move (motility) and their shape (morphology), along with the volume of the sample.
Why it is done
It is used to investigate fertility problems in couples trying to conceive, to check the success of a vasectomy, and sometimes to assess the effects of treatment or conditions affecting sperm.
What to expect
You produce a sample by masturbation, usually after a few days without ejaculating, into a sterile pot. It must reach the laboratory quickly and kept near body temperature; you may produce it at home nearby or at the clinic.
Understanding the results
Results are compared with reference values for count, motility and shape. Abnormal results may be repeated after a few weeks, as sperm quality varies, and can lead to further tests or fertility treatment.
Good to know
Risks and limitations
It is a safe test, but results vary over time and are affected by illness, timing and how the sample is handled, so it is often repeated before conclusions are drawn.
Education and reference only. This explains the test in general terms and is not medical advice. Always follow the specific instructions from the team arranging your test, and discuss your results with your clinician.
Answers
Semen Analysis: frequently asked questions
Why might a semen analysis need repeating?
Sperm production varies over weeks and can be affected by illness, fever and timing, so a single abnormal result is often confirmed with a repeat test a few weeks later.
How long should I abstain before the test?
A short period without ejaculating, usually a few days (commonly two to five), is recommended, as this gives the most representative sample. The clinic will give you exact instructions.
Related tests
Other other investigations
Sources
Where this is drawn from
- NHS — Tests and treatments
- NICE — diagnostic guidance
- Association for Laboratory Medicine / relevant professional body
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