Sperm health
Sperm vitality
Sperm vitality is the percentage of live sperm. The lower reference limit is 54%. It is most useful when motility is low.
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Short answer
Vitality is the percentage of sperm that are alive. The lower reference limit cited by NICE is 54% live. It is not the same as motility. A sperm can be alive and not progressive, and a dead sperm cannot be motile. Many standard reports omit vitality unless motility is low.
Key takeaways
- 54% or more live sperm is within the current reference range.
- The test uses a dye or a swelling method. It is not a guess from the motility percentage.
- Low vitality with low motility raises different questions from immotile sperm that are still alive.
- The decoder treats vitality as optional because your laboratory may not have reported it.
| Measurement | Reference value | How to read it |
|---|---|---|
| Semen volume | 1.4 ml or more | Within the current reference range at or above this value |
| Sperm concentration | 16 million/ml or more | Within the current reference range at or above this value |
| Total sperm number | 39 million or more | Within the current reference range at or above this value |
| Total motility | 42 % or more | Within the current reference range at or above this value |
| Progressive motility | 30 % or more | Within the current reference range at or above this value |
| Vitality | 54 % or more | Within the current reference range at or above this value |
| Normal morphology | 4 % or more | Within the current reference range at or above this value |
NICE also cites semen pH of 7.2 or more. These are lower reference limits, not a fertility diagnosis.
When it is requested
If few sperm are moving, the laboratory may stain the sample to see whether the immotile cells are dead. A low vitality result means many sperm are dead. A normal vitality result with very low motility means many are alive but not swimming. Those findings point clinicians in different directions, including whether a technical problem during collection is likely.
Do not invent it from motility
You cannot convert 30% total motility into a vitality percentage. If vitality is blank on your report, leave it blank in the decoder. An empty field is not counted as zero.
Related
Sources
- WHO laboratory manual for the examination and processing of human semen, 6th edition — World Health Organization, 2021
- Fertility problems: assessment and treatment (NG257) — NICE, 2026
- NG257: investigation of fertility problems and management strategies — NICE, 2026
- Low sperm count — NHS
How this page was prepared
Drafted with automated research assistance and checked against the cited primary sources. A named clinician has not reviewed this page. Medical review is pending. Changes to reference values are not published automatically.