Fertility · Male Factor
Semen Analysis — Male Fertility Test
When to test (1 year trying), how to collect, WHO 2021 reference values, what each parameter means, lifestyle improvements, varicocele, azoospermia, ICSI options. NICE NG156.
Last reviewed June 2, 2026
Semen analysis (WHO 2021 6th edition)
5th percentile lower reference limits
| Parameter | Lower limit | Your value | Flag |
|---|---|---|---|
| Volume | 1.4 mL | — | |
| Concentration | 16 million/mL | — | |
| Total sperm count | 39 million/ejaculate | — | |
| Total motility | 42 % | — | |
| Progressive motility | 30 % | — | |
| Normal morphology (strict Kruger) | 4 % | — | |
| pH | 7.2 | — | |
| Vitality (live sperm) | 54 % | — |
Educational tool only — not medical advice. WHO 2021 reference limits are the 5th percentile of fertile men (men who achieved pregnancy within 12 months of trying with their partner) — not a threshold below which fertility is impossible. About 5 % of men with normal fertility have values below these limits, and conversely some men above the limits have unexplained infertility. Interpretation requires the full clinical picture.
What does this mean?
The WHO 2021 6th edition replaced the 2010 5th edition with updated reference values from a larger international cohort of fertile men. The headline change: nothing dramatic — most values are stable, though concentration moved from 15 to 16 million/mL and progressive motility from 32 % to 30 %. Two big concepts: (1) these are 5th percentile values from FERTILE men, not thresholds for fertility — 5 % of fertile men’s samples fall below these numbers, and many men below them conceive without intervention. (2) A single sample is never definitive — spermatogenesis takes ~64–74 days, so repeat at 4–12 weeksbefore interpreting persistent abnormality. Combined abnormalities have nicknames: oligo (low count) + astheno (low motility) + terato (poor morphology) = OAT — the commonest pattern in male factor infertility. Azoospermia (no sperm at all) gets a separate workup (FSH, testosterone, karyotype, Y-chromosome microdeletions, possibly testicular biopsy).
Why test?
Male factor contributes to ~40-50% of fertility issues. NICE NG156: semen analysis after 1 year of regular unprotected intercourse without pregnancy (6 months if female partner ≥36).
How to collect
- By masturbation into sterile container.
- Private clinic room OR at home (delivered to lab within 1h, body temp).
- 2-7 day abstinence before sample.
- Entire ejaculate captured.
- No lubricant (kills sperm); semen-friendly lube OK (Pre-Seed).
- Avoid alcohol, smoking, hot baths in days prior.
WHO 2021 reference values
- Volume ≥1.4 mL.
- Concentration ≥16 million/mL.
- Total sperm count ≥39 million.
- Progressive motility ≥30%.
- Total motility ≥42%.
- Normal morphology ≥4% (Kruger strict).
- Vitality ≥54%.
- pH ≥7.2.
Lower 5th percentile of fertile men — not absolute cutoffs.
If abnormal, what next
Repeat in 6-8 weeks. Sperm production cycle is ~75 days.
Possible causes:
- Recent illness / fever.
- Varicocele (~30% of low counts).
- Hormonal imbalance.
- Genetic (Y microdeletions, Klinefelter).
- Infections (chlamydia, mumps).
- Medications (chemo, anabolic steroids, opioids).
- Recreational drugs.
- Radiation exposure.
Lifestyle improvements
- Stop smoking.
- Alcohol moderation.
- Weight if BMI ≥30.
- Avoid heat (hot baths, saunas, laptops on lap, tight underwear).
- Stress reduction.
- Moderate exercise (not extreme).
- Mediterranean diet + antioxidants + zinc + selenium + folate.
- Avoid anabolic steroids.
- 3 months for improvement to show.
Varicocele
Varicose veins in scrotum. 15% of men; ~30% of those with low counts. Raises testicular temperature.
Diagnosis: physical exam + scrotal ultrasound. Treatment: varicocelectomy or embolisation. Cochrane 2021: improves parameters; modest pregnancy impact.
Azoospermia
- Obstructive: blockage. Surgical sperm extraction (TESE/MESA) + ICSI.
- Non-obstructive: testes not producing. Micro-TESE may find pockets.
Karyotype + Y microdeletion testing standard. Referral to fertility specialist + urologist.
Anabolic steroids / TRT
Devastate sperm production. Negative feedback shuts testes down. Azoospermia common. Recovery possible after stopping (months); sometimes permanent.
Alternatives if fertility desired: clomiphene, gonadotropin injections (HCG/FSH), letrozole.
Different scenarios
Scenario 1: Trying 14 months, normal partner cycle
GP referral. Female + male workup. Semen analysis + ovulation tests.
Scenario 2: Sperm count 8 million/mL on first analysis
Repeat in 6-8 weeks. Lifestyle review. Hormone tests if confirmed low.
Scenario 3: Azoospermia on two analyses
Urology + fertility specialist. Hormone + genetic tests. TESE possibility.
Scenario 4: Previous chemotherapy 5 years ago, now trying
Early semen analysis. Possible cryopreservation in retrospect not possible. Donor sperm option discussed if needed.
Scenario 5: Anabolic steroid use 6 months stopped
Sperm recovery 6-12 months typically. Repeat analysis. Clomiphene/HCG to support recovery if needed.
Care guidance — semen analysis
- 2-7 day abstinence.
- No lubricant unless semen-friendly.
- Avoid heat, smoking, alcohol.
- Repeat abnormal results 6-8 weeks.
- Lifestyle changes take 3 months.
- Hormone tests if persistent low.
- Karyotype if azoospermia / very low count.
- Fertility specialist referral as needed.
- Mental health support — fertility journey hard.
- Partner involvement important.
Sources
- NICE NG156. Fertility problems: assessment and treatment.
- WHO Laboratory Manual for the Examination and Processing of Human Semen, 6th edition (2021).
- Fertility Network UK. fertilitynetworkuk.org.
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Frequently asked questions
Why might my partner need a semen analysis?
MALE FACTOR contributes to ~40-50% of fertility issues. NICE NG156: semen analysis after 1 YEAR of regular unprotected intercourse without pregnancy (12 months); EARLIER if ≥35 or known risk factor (chemo, surgery, undescended testis as child, varicocele, infections, anabolic steroids). PROCEDURE simple — provides sperm count, motility, morphology, volume. INFORMS NEXT STEPS in fertility journey.
How is the sample collected?
BY MASTURBATION into sterile container provided by clinic. PRIVATE ROOM at clinic OR at home (delivered to lab within 1 hour, kept body temp). 2-7 DAY ABSTINENCE before sample (no ejaculation 2-7 days — fewer/more can affect results). ENTIRE EJACULATE captured. NO LUBRICANT (kills sperm); special semen-friendly lube if needed (Pre-Seed is OK). LABELLED clearly with name + collection time. AVOID alcohol, smoking, very hot baths in days prior.
What's measured in a semen analysis?
WHO 2021 6th edition reference values: (1) VOLUME ≥1.4 mL; (2) CONCENTRATION ≥16 million/mL; (3) TOTAL SPERM COUNT ≥39 million; (4) PROGRESSIVE MOTILITY ≥30%; (5) TOTAL MOTILITY ≥42%; (6) NORMAL MORPHOLOGY ≥4% (strict Kruger criteria); (7) VITALITY ≥54%; (8) pH ≥7.2. LOWER 5th percentile of fertile men — not absolute cutoffs (men below can still father children; men above can still have issues). MULTIPLE FACTORS combined matter.
What if numbers are abnormal?
REPEAT in 6-8 WEEKS — sperm production takes ~75 days; one bad sample doesn't define fertility. POSSIBLE CAUSES: (1) RECENT ILLNESS / fever (resolves); (2) VARICOCELE (~30% of men with low counts); (3) HORMONAL imbalance (low testosterone, high prolactin); (4) GENETIC (Y chromosome microdeletions, Klinefelter 47,XXY); (5) INFECTIONS (chlamydia, mumps); (6) MEDICATIONS (chemotherapy, anabolic steroids, opioids); (7) RECREATIONAL DRUGS; (8) RADIATION exposure; (9) UNKNOWN. INVESTIGATIONS: hormones (FSH, LH, testosterone, prolactin); scrotal ultrasound; karyotype/Y-microdeletion if very low count.
Can lifestyle improve sperm?
YES — sperm production responds to lifestyle changes over 3 months. (1) STOP SMOKING (reduces count, motility, DNA quality); (2) ALCOHOL moderation (heavy drinking = lower count); (3) WEIGHT loss if BMI ≥30 (improves hormone balance); (4) AVOID HEAT — hot baths, saunas, laptops on lap, tight underwear; (5) STRESS reduction; (6) EXERCISE moderate (not extreme — over-training can harm); (7) DIET: Mediterranean style; antioxidants; folic acid; zinc; selenium; vitamin C/D; (8) AVOID anabolic steroids; recreational drugs; (9) AVOID exposure to phthalates, pesticides where possible; (10) TIME — improvements take 3 months minimum.
What's a varicocele?
VARICOSE VEINS in scrotum. Common (15% of men). Larger ones can RAISE testicular temperature → impair sperm production. ~30% of men with abnormal semen analysis have varicocele. DIAGNOSED: physical exam ('bag of worms'); scrotal ultrasound confirms. TREATMENT: surgical repair (varicocelectomy); embolisation. EVIDENCE: Cochrane 2021 — surgery improves sperm parameters; modest impact on pregnancy rates. NOT all varicoceles cause issues; many men with them father normally.
What's azoospermia?
NO SPERM in ejaculate. ~1% of men, 10-15% of infertile men. TWO TYPES: (1) OBSTRUCTIVE (blockage from epididymis, vasectomy, vas deferens absent — CBAVD, infection scarring); sperm produced but can't get out. Treated by surgery or surgical sperm extraction (TESE/MESA) + ICSI. (2) NON-OBSTRUCTIVE (testes not producing sperm — hormonal, genetic). May still find pockets of sperm in testis via micro-TESE. KARYOTYPE, Y MICRODELETION testing standard. REFERRAL to fertility specialist + urologist.
Can I use my own sperm for IVF / ICSI?
DEPENDS on parameters. IVF (in vitro fertilisation): standard IVF needs reasonable count + motility (~5 million motile per IVF cycle ideal). ICSI (intracytoplasmic sperm injection): only needs 1 viable sperm per egg — even very low counts can work. SEVERE male factor → ICSI usual. DONOR SPERM option if no viable sperm or genetic concerns. DISCUSSED with fertility specialist based on individual results.
What about sperm DNA fragmentation?
ADVANCED TEST: assesses DNA integrity in sperm. HIGH FRAGMENTATION associated with: lower fertility; recurrent miscarriage; failed IVF. CAUSES: oxidative stress, infection, varicocele, smoking, age, environmental toxins. NICE / RCOG: not routine; selected use. TESTS: TUNEL, SCSA, COMET. TREATMENT: lifestyle changes; antioxidants; varicocele repair if present; for IVF — testicular sperm sometimes preferred over ejaculated.
Does age affect male fertility?
YES — though less dramatic than female. SPERM QUALITY declines from ~40: lower count, motility; higher DNA fragmentation; small increase in chromosomal abnormalities; very slightly increased autism/schizophrenia risk in offspring. FATHERING POSSIBLE into 70s+ for many but reduced rates + longer time to conceive. NEVER 'too late' but recommend not waiting unduly if family planning. PRE-CONCEPTION optimisation works at any age.
What about anabolic steroids / testosterone?
ANABOLIC STEROIDS / EXOGENOUS TESTOSTERONE devastate sperm production. Negative feedback suppresses gonadotropins → testes shut down. AZOOSPERMIA common. CAN RECOVER — usually months after stopping; sometimes permanent damage if used long-term. TRT (testosterone replacement therapy): same effect. ALTERNATIVES if fertility desired: clomiphene, gonadotropin injections (HCG/FSH), letrozole — preserve fertility. DISCUSS with endocrinology before starting testosterone if family planning ahead.
How long until results?
Usually 5-10 working days. SOME labs same-week. Repeat at 6-8 weeks if abnormal — sperm production cycle 75 days. CONSULT with GP / fertility specialist to discuss; sometimes results discussed at follow-up appointment. PRIVATE labs: faster turnaround (24-72 hours possible).
Can stress affect sperm?
MILD STRESS: minimal impact. CHRONIC SEVERE stress: can suppress hormones, reduce libido, decrease sperm parameters. MEN'S MENTAL HEALTH important — fertility journey itself stressful. PARTNER CONCEALMENT of fertility issues common; need for openness. SUPPORT: counselling, fertility support charities (Fertility Network UK), peer groups.
When should we see a fertility specialist?
NICE NG156: AFTER 1 YEAR trying without pregnancy (or 6 months if woman is ≥36). EARLIER if: known risk factors; very abnormal semen analysis; menstrual irregularity in partner; previous fertility issues. GP CAN INITIATE: hormone tests, semen analysis, basic referral. FERTILITY CLINIC referral after initial investigation. NHS criteria for IVF vary by area; private always available.
How does this relate to other calculators on BumpBites?
Companion: /calculators/fertility-window for couples trying; /calculators/ovulation; /calculators/fertility-tracking-accuracy; /calculators/pregnancy-test-timing; /calculators/recurrent-miscarriage (partner contribution); /calculators/implantation; /calculators/conception-date.