How to read your semen analysis report

Three things to know before you read any number

The ranges come from fertile men

WHO 2021 limits are the 5th centile of about 3,500 men whose partners conceived within 12 months. One in twenty fertile men was below each line.^[1]

Below the line is not a diagnosis

The manual says a single value below the 5th centile is not sufficient, by itself, to diagnose infertility. Guidelines weigh all values together with exam and history.^[2]^[4]

One test is a snapshot

Counts vary about 50% within the same man. Both major guidelines ask for two analyses, about a month apart, before conclusions.^[4]^[5]

WHO 2021 reference distribution, line by line

Centiles among fertile men. The 5th is the "lower reference limit" printed on most reports. If your report prints different limits (15 million/mL, 40% motility, 32% progressive, 58% vitality), it is using WHO 2010.^[3]

Parameter	Unit	5th	25th	50th	75th	95th
Semen volume How much fluid. Low volume with a low count points to collection problems or, rarely, obstruction.	mL	1.4	2.1	3.0	4.2	6.2
Sperm concentration Sperm per millilitre. Moved from 15 to 16 in 2021.	million/mL	16	30	66	110	208
Total sperm number Volume × concentration. Usually more informative than concentration alone.	million	39	96	210	363	802
Total motility Share moving in any way. Was 40% in WHO 2010.	%	42	55	64	72	81
Progressive motility Share swimming forward. Was 32% in WHO 2010.	%	30	43	55	62	72
Non-progressive motility Moving but not getting anywhere.	%	1	3	5	7	14
Immotile Not moving. The median fertile man has 35%.	%	20	27	35	45	56
Vitality Share alive. Requested when total motility is under about 40%.	% live	54	65	79	88	97
Normal forms (morphology) Share with strict textbook shape. Most subjective value on the report.	%	4	9	14	20	36

Source: WHO laboratory manual, 6th edition (2021), reference distributions.^[1] Each of the three main parameters has its own explainer: morphology, concentration, motility.

The one calculation worth doing

Volume × concentration × total motility = total motile sperm count (TMSC), in millions. In 1,177 couples followed for three years, TMSC bands of under 5, 5–20 and over 20 million separated spontaneous pregnancy chances better than any single WHO parameter.^[6] The numbers box on the home page calculates it and places each value on the reference range. Nothing you type leaves your browser.

What guidelines describe after an abnormal result

Repeat the analysis about a month later with the same abstinence and a complete collection.^[4]
History and physical exam, including a check for varicocele and testicular size.^[4]
Hormones (FSH, testosterone) when the count is low or zero.^[4]^[5]
Genetic tests when concentration is below 5 million/mL (karyotype) or at or below 1 million/mL (Y-chromosome microdeletions), with conditions.^[4]^[5]
A plan based on the whole picture, including the partner's evaluation and time trying. Low TMSC on repeated tests shifts the IUI-versus-IVF discussion.^[4]

Guidelines do not recommend routine DNA fragmentation testing at the first visit, testosterone for men trying to conceive, or supplements as a treatment plan.^[4]

Eight questions to bring to the appointment

Which WHO edition and which morphology criteria did the lab use?
What is my total sperm number and my total motile sperm count?
Which values, if any, are below the reference limit, and how many of them are there?
When should the repeat test be, and should the abstinence length match the first?
Did the exam find a varicocele? Is it palpable?
Do my numbers trigger hormone or genetic testing?
What would change the plan: the repeat result, the exam, or my partner's evaluation?
What should I not do in the meantime (testosterone, heat, specific supplements)?

Glossary

Reference limit / 5th centile

The value that 95% of fertile men (partner pregnant within a year) were above. One in twenty fertile men was below it. It is a reference point, not a pass/fail line, and the WHO states it is not sufficient on its own to diagnose infertility.

Median / 50th centile

The middle value among fertile men: half had less, half had more.

Oligozoospermia

Concentration below 16 million/mL. 'Severe' usually means below 5 million/mL.

Asthenozoospermia

Motility below the reference limit.

Teratozoospermia

Normal forms below 4%.

OAT

Oligo-astheno-teratozoospermia: all three below their limits at once. Guidelines give this pattern more weight than any single abnormality.

Azoospermia

No sperm found. Needs confirmation on a second centrifuged sample, then a work-up that separates obstruction from impaired production.

TMSC

Total motile sperm count: volume × concentration × total motility, in millions. Outcome studies group it as under 5, 5–20, and over 20 million.

Post-wash / inseminating motile count

The motile sperm actually placed in the uterus at IUI, after lab preparation. Below about 5 million, IUI success falls.

Agglutination

Sperm sticking together in clumps; may prompt an antibody test.

Leukocytes (round cells)

White cells; above 1 million/mL may prompt an infection work-up, though its importance is debated.

pH

Acidity. Low pH with low volume and no sperm suggests obstruction or absent vas deferens.

Liquefaction

How long the sample takes to turn from gel to liquid; usually under 30–60 minutes. Delays can affect measurement.

Abstinence

Days since last ejaculation before the sample. WHO asks for 2–7 days; keep it the same between tests.

Sources

WHO 6th-edition reference distributions, reproduced in PMC — primary table. https://pmc.ncbi.nlm.nih.gov/articles/PMC12539902/table/t1/
Boitrelle F et al. Critical review of the WHO 6th edition. Life 2021 — primary. https://pmc.ncbi.nlm.nih.gov/articles/PMC8706130/
WHO 2010 vs 2021 reference values compared. Andrology 2022 — abstract. https://onlinelibrary.wiley.com/doi/10.1111/andr.13213
AUA/ASRM Guideline on Male Infertility (2024 amendment) — primary. https://www.auanet.org/guidelines-and-quality/guidelines/male-infertility
EAU Guidelines: Male Infertility — primary. https://uroweb.org/guidelines/sexual-and-reproductive-health/chapter/male-infertility
Hamilton JA et al. Total motile sperm count. Hum Reprod 2015 — primary. https://academic.oup.com/humrep/article-lookup/doi/10.1093/humrep/dev058