Semen Analysis Results Explained, Line by Line
A semen analysis report is one page: your values in one column, reference values in the next, a flag in the margin where the two disagree. Most men read it like a blood test — above the line fine, below the line trouble — and most are wrong about what the line is.
The reference values are not a pass mark. They describe where the bottom of a fertile population sits, and that fact changes how every other number should be read. The male fertility test page covers the test; this one takes the report apart.
The reference values, and what they really are
This is the part most often misexplained, including by clinicians in a hurry.
The values come from the World Health Organization, derived in a particular way: investigators measured the semen of men whose partners had conceived within a year of trying — men with recent, demonstrated fertility — and published the distribution. The reference value for each parameter is the lower fifth centile of it.
In plain terms: ninety-five percent of recently fertile men sat above it, and five percent — men who had just fathered children — sat below. The value marks the bottom edge of a fertile group, not a boundary between fertile and infertile. No such boundary was ever measured.
That cuts both ways. Men below the reference values father children, constantly; a value under the line lowers the odds and tells a clinician where to look, but it does not put conception off the table. And men comfortably above every value are sometimes in couples who cannot conceive, which is why a normal report does not close an investigation.
A semen analysis shifts probabilities and points at what to investigate next. It does not issue verdicts. That is not a hedge; it is what the study design supports.
Going down the sheet
Volume. How much fluid was produced. Most of it comes from the seminal vesicles and prostate rather than the testes, so a low volume usually reflects those glands, the abstinence interval, or part of the sample being spilled — not sperm production. Repeatedly low volume with a low count can point toward an obstruction or retrograde flow into the bladder: worth investigating, not diagnosable from this line. Collection technique has its own page, preparing for a semen analysis.
Sperm concentration. How densely packed the sperm are in the fluid — what the internet means by "sperm count." Being a ratio, it is sensitive to volume: a large dilute sample and a small dense one can hold the same number of sperm and report very different concentrations.
Total sperm count. Concentration multiplied by volume — the number in the whole ejaculate, and usually the more meaningful of the two, because it is closer to what the testes actually produced.
Progressive motility. The proportion moving forward purposefully, rather than twitching in place or not moving at all — the movement that matters for reaching an egg, which is why it is separated from total motility. It is also the value most damaged by delay and temperature in transit: a sample that sat too long describes the courier rather than the man. If motility is your only abnormal value and the return was slow, repeat before concluding anything. See at-home vs clinic analysis.
Morphology. The proportion judged normally formed against strict criteria — its own section, below.
Vitality. The proportion alive, by stain or swelling test. It exists mainly to interpret poor motility: alive but not swimming points at a structural problem rather than cell death. Not every panel reports it.
Morphology: the most over-read number on the page
Morphology causes more distress than any other line and deserves the least of it.
Strict criteria were built to be demanding. A sperm counts as normal only if head, midpiece and tail all fall within tight limits, and by that standard the great majority of sperm in an entirely ordinary fertile man are classified abnormal. A low-looking percentage is the expected finding, not the alarming one; reading it as "most of my sperm are deformed" misunderstands what the assessment was built to do.
It is also the most operator-dependent measurement on the sheet — a stained slide, a trained technician, a subjective judgment repeated across a few hundred cells. Different laboratories, and different technicians within one laboratory, return meaningfully different results on the same sample. That is why external quality programs exist for andrology laboratories.
The large study comparing fertile and infertile men found no parameter that cleanly separated the groups, morphology included; the distributions overlapped substantially. Morphology in isolation, everything else normal, is the weakest reason to act this report can generate.
Why one result is never acted on
Sperm take roughly two and a half months to develop into a cell that appears in an ejaculate, so a fever, a medication, a punishing training block or a bad stretch of sleep anywhere in that window is in the sample. The report photographs a window; it does not measure a fixed property of your body.
So a single abnormal result is repeated before anyone treats, refers or worries on the strength of it — far enough out to sample a different production window. Two consistent results are a picture. One is a snapshot, and a snapshot can be of the two weeks you had the flu.
What usually comes next
If a repeated result is genuinely abnormal, the next step is not a treatment. It is a hormone panel — testosterone, LH, FSH and prolactin — which answers one question: signaling problem, or testicular one?
LH and FSH are the pituitary's instructions to the testis. High instructions with low production mean the message is being sent and the testis is not responding. Low or inappropriately normal levels alongside low testosterone mean the signal itself is the problem, and the cause sits upstream. Prolactin is checked because an elevation there can suppress the whole axis. Different problems, different destinations, and the semen report cannot tell them apart — see lab testing.
Some findings belong with someone else: a varicocele, a suspected obstruction, or a very low count with a hormonal picture suggesting a genetic cause need a urologist or a reproductive specialist, and we will say so rather than keep you inside our own service. If you are on, or considering, testosterone therapy, read testosterone therapy and fertility first.
Frequently asked questions
You are below the lower fifth centile of men whose partners conceived within a year. It lowers the odds and tells a clinician where to look. It is not a diagnosis of infertility, and men below these values father children.
No. It is the most subjective, the most operator-dependent and the most over-interpreted. Alone, with everything else normal, it is rarely a reason to act.
Yes. Within-person variation is large enough that standard practice is a repeat some weeks later before anything is acted on.
Concentration is sperm per unit of fluid; total count is concentration multiplied by volume — the number in the whole sample, and usually the more meaningful figure.
Because forward movement is what matters for reaching an egg. It is also the parameter most affected by delay and temperature in transit, which is why timing instructions matter.
Usually a hormone panel — testosterone, LH, FSH and prolactin — which distinguishes a signaling problem from a testicular one, and often changes what the semen result means.
Where this fits in your plan
The male fertility test replaces an assumption with a measurement. The reading of it — against your history, your medications, your last few months — is where the value sits. Read without that context, a report is a page of numbers with a line drawn in the wrong place.
We measure first. Then we act.
References
- World Health Organization. WHO laboratory manual for the examination and processing of human semen. Sixth edition. Geneva: World Health Organization, 2021.
- Cooper TG et al. World Health Organization reference values for human semen characteristics. Human Reproduction Update 2010;16:231–245.
- Guzick DS et al. Sperm morphology, motility, and concentration in fertile and infertile men. New England Journal of Medicine 2001;345:1388–1393.
- Schlegel PN et al. Diagnosis and treatment of infertility in men: AUA/ASRM guideline, Part I. Fertility and Sterility 2021.
- Practice Committee of the American Society for Reproductive Medicine. Diagnostic evaluation of the infertile male: a committee opinion. Fertility and Sterility.
- Björndahl L, Barratt CLR, Mortimer D, Jouannet P. 'How to count sperm properly': checklist for acceptability of studies based on human semen analysis. Human Reproduction 2016.
- Back toMale Fertility Test
- Preparing for a semen analysisThe abstinence window, the ten-week lookback, heat, medications and return timing — what decides whether your semen analysis is worth reading.Read
- At-home vs clinic analysisMail-in kit, consumer device, or a clinic andrology lab? What each one measures well, where each one fails, and when a formal analysis is worth the trip.Read
- Age and sperm qualityNo cliff, but no free pass either. What ages in sperm, what does not, how to read paternal-age risk honestly, and what is still worth changing.Read
- All lab testsA comprehensive blood panel establishing your baseline across key health markers.Read
- For menTestosterone therapy, weight loss, recovery, sexual wellness and longevity.Read
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ACT 2 Health provides clinician-led care. Treatments are available only to eligible patients following clinical evaluation and within applicable regulations. This content is educational and is not medical advice. Individual results vary.
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