The semen analysis
The first test is a semen analysis. A lab looks at how much semen there is, how many sperm it contains, how well they move and what they look like. NICE asks labs to compare results with the World Health Organization reference values, which include:
- Volume: 1.4 ml or more
- Concentration: 16 million sperm per ml or more
- Total motility (sperm that move): 42% or more
These are reference values, not a pass or fail line. Plenty of men below them father children, and a result above them does not guarantee anything. Results usually go to the doctor who referred you, who should talk them through with you.
If a result comes back low
One low result is not a diagnosis. Sperm counts vary from week to week, and an illness or fever in the previous months can lower them. NICE recommends repeating an abnormal test, ideally about 3 months later, because that is roughly how long sperm take to form. If no sperm or very few are found, the repeat should happen as soon as possible.
After two or more abnormal results, a doctor may examine the testicles and check hormone levels with a blood test. If the count stays very low, a genetic test may be offered.
Treatment
What is offered depends on the cause. The main routes:
- ICSI (intracytoplasmic sperm injection): an embryologist injects a single sperm into each egg. It is the most common treatment for male infertility, because it needs far fewer sperm than standard IVF.
- Surgical sperm retrieval: if there is a blockage, or the testicles are not releasing sperm, sperm can sometimes be collected directly from the testicle or epididymis (procedures called PESA, TESA, TESE and microTESE). It is used with ICSI, and sperm can be frozen for later cycles.
- Donor sperm: where no sperm can be retrieved, or a couple prefers it, donor sperm is an option. The guide to choosing a donor covers how it works in the UK.
When to see a GP
If you have been trying for a baby for 12 months without success, see your GP; they can arrange a semen analysis. Go sooner if you have had undescended testicles, an injury to the testicles or a sexually transmitted infection.
Sources
- NICE NG257, Investigation of fertility problems and management strategies (2026) (opens in a new tab)
- HFEA, Intracytoplasmic sperm injection (ICSI) (opens in a new tab)
- HFEA, Infertility surgery for men (opens in a new tab)
- Fertility Network UK, Male fertility FAQs (opens in a new tab)
Last reviewed 8 October 2026. General information, not medical or financial advice. Your clinic and a regulated adviser can advise on your situation.