How to read your semen analysis (WHO 2021 reference values)
A semen analysis report is a wall of numbers with no context, and it's easy to spiral over one line. Here's what each value actually measures, the reference limits the labs use, and why a single result is never the whole story.
The reference limits (WHO 2021, 6th edition)
The World Health Organization's lower reference limits come from the 5th percentile of men who fathered a child within 12 months. Below them doesn't mean "infertile", it means you're below where most recently-fertile men sit, and worth a closer look.
Semen volume: 1.4 mL. Sperm concentration: 16 million per mL. Total sperm number: 39 million per ejaculate. Total motility: 42%. Progressive motility: 30%. Normal morphology: 4%. Vitality: 54% live. Those are the numbers your lab is comparing against.
What each one actually tells you
Concentration is sperm per mL; total count is concentration times volume, and is often the more meaningful figure. Motility is the share that are swimming, progressive motility (moving forward, not just twitching) is what matters most for reaching an egg.
Morphology is the share with a normal shape, and 4% normal is the reference limit, yes, that low is expected, so don't panic at a number like 5%. Volume that's very low can point to a collection or plumbing issue rather than production. Azoospermia means no sperm found at all.
Why one result isn't a verdict
Semen parameters are genuinely noisy, they swing with abstinence time, a recent illness or fever, stress, and even how the sample was collected and handled. A single low result is a reason to retest, not a diagnosis.
Most clinicians want at least two samples a few weeks apart before drawing conclusions. And because sperm take about 2.5 to 3 months to be produced, a test only reflects what your body was doing months ago, so retesting two weeks after a change tells you nothing.
Getting a clean sample
For a representative result, labs generally ask for 2 to 7 days of abstinence beforehand, not zero, not two weeks. Keep the sample near body temperature and get it to the lab quickly, since sperm degrade when it sits or cools.
If a result is off, ask about repeating it under good conditions before you act on it. This is general planning information, not medical advice, a clinician should interpret your specific report alongside your history and hormones.
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Get my fertility plan →Common questions
What is a normal sperm count?
By WHO 2021 reference limits, 16 million/mL concentration or 39 million total per ejaculate is the lower bound, drawn from the 5th percentile of recently-fertile men. Above it is reassuring; below it is worth a retest and a closer look, not an automatic diagnosis.
Is 4% normal morphology bad?
No, 4% is actually the WHO reference limit. Under strict criteria, most normal, fertile men have a low percentage of perfectly-shaped sperm, so a number around 4% is expected rather than alarming.
Should I retest if my first result is low?
Yes. Semen parameters vary a lot with abstinence, illness and handling, so most clinicians want at least two samples a few weeks apart before concluding anything. And any recent protocol change won't show for about 90 days.
More guides
- How long does sperm take to recover after stopping TRT?→
- Can you take hCG on TRT to protect your fertility?→
- Sperm banking before TRT: how it works and what it costs→
- Does TRT cause permanent infertility?→
- How soon does TRT lower your sperm count?→
- Clomid vs hCG on TRT: which one protects your fertility?→
- On TRT and trying to conceive: what to do right now→
- Enclomiphene vs TRT: raising testosterone without killing fertility→
- FSH and hMG: what to do when hCG alone isn't restoring your count→
- hCG vs enclomiphene: which one actually protects fertility on TRT?→
- How to maintain fertility on TRT: the practical playbook→
- TRT and fertility: what every man should know before starting→
- Is enclomiphene safe? The side effects worth knowing about→
- Enclomiphene vs clomiphene: what's actually different?→
- How long does enclomiphene take to work?→
- Does enclomiphene work? What it actually does and when it falls short→
- Is enclomiphene a steroid?→
- Enclomiphene dosage for men: what clinicians typically use and why it isn't one-size-fits-all→
- Can testicular atrophy from TRT be reversed?→
- hCG instead of TRT: alternatives that protect your fertility→
- How much does sperm banking cost, and is it worth it before TRT?→
- How long after stopping testosterone does sperm count increase?→
- How often to take hCG on TRT, and does it actually preserve fertility?→
- Does age affect how fast sperm recovers after TRT?→
- Micro-TESE: when sperm recovery stalls and what comes next→
- World Health Organization. WHO laboratory manual for the examination and processing of human semen, 6th ed., 2021.
- Liu PY et al. Rate, extent and modifiers of spermatogenic recovery in normal men after male hormonal contraception. The Lancet, 2006.
Prezerv is a self-guided planning tool. It does not provide medical advice, diagnosis, or treatment. Always consult a qualified clinician about your own situation.