If you've just received a semen analysis report, the page of numbers and abbreviations can be hard to parse on your own. This guide walks through what each result measures, what counts as a typical value according to the current World Health Organization (WHO) reference ranges, and — just as importantly — what a single report can't tell you on its own.

This article is educational. It's not a diagnosis, and it doesn't replace a conversation with the clinician who ordered your test.

Quick reference: WHO 2021 lower reference limits

These are the lower reference limits from the WHO 6th edition laboratory manual (2021), as reproduced in the AUA/ASRM clinical guideline for male infertility. "Lower reference limit" means the 5th percentile of semen values from a reference population of recent fathers — in plain terms, about 95% of men in that fertile reference group scored at or above this number. It is not a pass/fail cutoff for fertility.

Two parameters that commonly appear on a report aren't part of the core WHO percentile table above, and are worth understanding separately: liquefaction time and white blood cell count. Both are covered below.

What a semen analysis actually measures

A semen analysis is a laboratory count and description of the sperm and fluid in an ejaculate sample. It's one part of a fertility evaluation — it doesn't measure DNA quality, hormone levels, or a partner's fertility, and it says nothing about spermatogenesis itself (the roughly two-to-three-month process by which sperm are produced, which is covered in detail in How Are Sperm Produced? Understanding Spermatogenesis Step by Step).

Reading each parameter on your report

Semen volume. This is simply how much fluid was in the sample, typically measured in milliliters. A low volume can sometimes reflect an incomplete collection, a short abstinence period, or — less commonly — issues with the seminal vesicles or ejaculatory ducts. A single low-volume result is common and doesn't by itself indicate a problem.

Sperm concentration. The number of sperm per milliliter of semen. This is one of the most frequently cited numbers on a report, but concentration alone doesn't determine fertility potential — it's one input among several, which is part of why total sperm number and total motile sperm count (below) are also useful.

Total sperm number. Concentration multiplied by volume — the total sperm present in the whole sample, rather than just per milliliter. This can differ meaningfully from concentration alone if volume is unusually high or low.

Total motility and progressive motility. These are often confused. Total motility is the percentage of sperm that show any movement at all. Progressive motility is the subset of those that are moving with purpose in a mostly straight line or in large circles — the movement pattern generally considered more relevant to reaching and fertilizing an egg. A report can show reasonable total motility with lower progressive motility, and the two numbers are worth reading together rather than separately.

Morphology. The percentage of sperm with a "normal" shape and structure under strict laboratory criteria (Kruger strict criteria are the most commonly used standard). Morphology reference limits are unusually low compared to what people expect — 4% is the WHO 2021 lower reference limit, meaning even many fertile men have sample morphology scores that look low in absolute terms. This is one of the more misunderstood numbers on a semen analysis report, precisely because a lay reader expects "normal" to mean "most."

Vitality. The percentage of sperm that are alive, distinguished from those that are simply not moving (immotile but alive) versus dead. Vitality testing is particularly useful when total motility is low, since it helps clarify whether low motility reflects dead sperm or live-but-immotile sperm — a distinction relevant to some assisted-reproduction decisions.

pH. A measure of the semen's acidity or alkalinity. The WHO reference value is 7.2. Unlike the parameters above, pH is used more as a laboratory quality/diagnostic marker than a percentile-based fertility indicator, and an isolated pH result outside the typical range is best interpreted by the clinician who ordered the test, in the context of the rest of the report.

Liquefaction time. Freshly ejaculated semen is initially thick and typically liquefies within roughly 15 to 30 minutes at body temperature, per Cleveland Clinic's patient-education material — this isn't a WHO percentile statistic but a practical lab observation about how the sample behaves. Delayed liquefaction can occasionally reflect issues with the prostate or seminal vesicles and is generally something the ordering clinician will follow up on directly rather than something to self-interpret.

White blood cells (leukocytes). Under WHO 2021 criteria, a semen sample with more than roughly 1.0 million peroxidase-positive white blood cells per milliliter is generally considered to reflect leukocytospermia, which can be associated with inflammation or infection in the reproductive tract. This finding, on its own, is not a diagnosis — it's typically a prompt for the clinician to look further, not a self-contained conclusion.

Total motile sperm count (TMSC)

TMSC is a calculated value — total sperm number multiplied by the percentage of progressively motile sperm — that some clinicians use as a combined snapshot rather than looking at concentration and motility in isolation. Unlike the parameters in the table above, TMSC does not have an official WHO 5th-percentile reference limit; different clinics and contexts (for example, when assessing candidacy for intrauterine insemination) may apply their own thresholds. If your report includes a TMSC figure, the most reliable way to interpret it is to ask the clinician or lab that generated it what threshold they're using and why, rather than comparing it to a number found online.

WHO 2021 vs. the older WHO 2010 values

If you've seen different "normal" numbers cited elsewhere — most commonly a sperm concentration cutoff of 15 million/mL rather than 16 million/mL — that's very likely because the source is still using the WHO 5th edition (2010) reference values rather than the current 6th edition (2021). The two editions are close but not identical: the current WHO 2021 lower reference limits for concentration, progressive motility, and vitality are each slightly different from the 2010 figures. If your actual lab report cites a different reference range than the one above, that's not necessarily an error — it likely means the laboratory is using its own validated reference range or a different edition, which is common and worth asking about rather than assuming something is wrong.

One result is not a diagnosis

This is the part most semen-analysis guides skip, and it matters: semen parameters vary naturally from one sample to the next in the same man, due to factors like the length of the abstinence period before the sample, recent illness or fever, stress, and even how the sample was collected and handled. Research looking specifically at repeat testing has found that when a first semen analysis comes back abnormal, only about half to two-thirds of those abnormal findings are still abnormal on a second sample — motility showed the lowest agreement between the two tests in that research (Hanson et al., F&S Reports, 2021).

Because of this variability, the current AUA/ASRM clinical guideline recommends obtaining at least two semen analyses, generally about a month apart, before drawing conclusions from an abnormal result. That said, the same body of more recent research suggests this one-month spacing isn't strongly evidence-based on its own, and that the most informative retest interval may depend on which parameter was abnormal and how far outside the reference range it was. In practice, this means: don't treat a single abnormal number as a verdict, and follow your clinician's specific guidance on when to retest rather than a fixed rule you find online.

What might explain an abnormal parameter

A single abnormal result can reflect many things — some temporary and some worth a closer look. Recent illness or fever, certain medications, a very short or very long abstinence period, and heat exposure in the weeks before the sample are all factors clinicians consider. CoolMen has separate, more detailed articles on some of the most common contributing factors if you want to go deeper: how temperature and heat exposure relate to sperm quality, common causes of male infertility more broadly, and varicocele, a common and treatable condition that can affect several of the parameters above. This article focuses on reading the report itself; those pages go deeper on specific causes.

What to do next

If your results were within the typical ranges, that's a genuinely reassuring data point, though fertility involves both partners and multiple factors beyond semen parameters alone. If one or more results were outside the reference range, the most evidence-based next step is a second semen analysis — generally about a month later, per current clinical guidance, though your clinician may suggest a different interval based on your specific results. Persistent abnormal results, or any additional symptoms like testicular pain, swelling, or a change you've noticed over time, are good reasons to see a urologist or fertility specialist (an andrologist) rather than trying to interpret repeated results on your own.

If you'd like to keep an eye on concentration and progressive motility between clinical visits — for example, while waiting on a retest or tracking a lifestyle change — the CoolMen Home Sperm Quality Test is designed for at-home monitoring of those two parameters. It's built to complement a laboratory semen analysis, not replace one, and it's currently available by waitlist as CoolMen brings it to market — you can join the waitlist here to be notified when it ships.

Frequently asked questions

Is a low sperm count the same as infertility? No. A result below the WHO reference range means your value fell below the 5th percentile of a fertile reference population — it's associated with a statistically lower chance of natural conception, but many men with below-range results still conceive, and fertility depends on multiple factors in both partners, not on one parameter in isolation.

How soon can I get retested? Current clinical guidance generally suggests waiting about a month before a repeat semen analysis, though your clinician may recommend a different interval depending on which parameter was abnormal and by how much.

Can I track my sperm health at home between lab tests? Some at-home devices, including the CoolMen Home Sperm Quality Test, are designed to give a preliminary read on concentration and motility for tracking purposes. These tools are meant to complement — not replace — a laboratory semen analysis, and any concerning or unexpected result should still be discussed with a healthcare professional.

Does one abnormal parameter mean I need IVF or another fertility treatment? Not necessarily. Treatment decisions depend on the full clinical picture — which parameters are affected, by how much, whether results are consistent across repeat testing, and factors relating to your partner if you're trying to conceive together. A single number is a starting point for a conversation with a specialist, not a treatment decision on its own.

Sources

• World Health Organization. WHO laboratory manual for the examination and processing of human semen, 6th edition (2021) — publication record: https://www.who.int/publications/i/item/9789240030787
  
• Reference values reproduced and cross-checked via: NHS Manchester University NHS Foundation Trust, "Lower reference limits for semen characteristics" (2021): https://mft.nhs.uk/app/uploads/sites/4/2023/01/Lower-reference-limits-2021.pdf
  
  
• American Urological Association / American Society for Reproductive Medicine. "Diagnosis and Treatment of Infertility in Men" guideline (2020, amended 2024) — Table 4 (WHO 2021 reference values) and Guideline Statement 2 (repeat semen analysis recommendation): https://www.auanet.org/documents/Guidelines/PDF/2024%20Guidelines/Male%20Infertility%20Unabridged%20Final.pdf
  
  
• Hanson BM, et al. "Optimal timing for repeat semen analysis during male infertility evaluation." F&S Reports, 2021. https://pmc.ncbi.nlm.nih.gov/articles/PMC8267395
  
  
• Cleveland Clinic. "Semen Analysis: Purpose, Procedure & Results." https://my.clevelandclinic.org/health/diagnostics/21520-semen-analysis (used only for liquefaction time, attributed accordingly rather than presented as a WHO figure)
  
  
• CoolMen Home Sperm Quality Test product page https://becoolmen.com/products/coolmen-home-sperm-quality-test

This article is for educational purposes and does not replace individualized medical advice. If you have concerns about your results, speak with the clinician who ordered your test or a qualified fertility specialist.