Male fertility: semen analysis and sperm health
Getting tested
A semen analysis should be among the first tests when a couple has difficulty conceiving. It is inexpensive, non-invasive and quick — and male assessment is still routinely delayed in favour of investigating the female partner first.
Collection matters. Two to seven days of abstinence. Complete collection, including the first portion, which carries most of the sperm. Prompt delivery to the laboratory — delay and temperature extremes reduce motility.
An abnormal result should always be repeated. Parameters vary substantially between samples from the same man.
Reading the report
WHO 6th edition (2021) lower fifth percentile: volume 1.4 mL, concentration 16 million/mL, total number 39 million, total motility 42%, progressive motility 30%, vitality 54%, normal forms 4%.
Two things to understand about these figures:
They are not a fertile/infertile threshold. WHO states this explicitly, and notes substantial overlap between fertile and infertile men.
Total sperm number matters more than concentration. WHO notes it has greater diagnostic value — but only where semen volume is measured accurately. If your report gives concentration without total number, ask for it.
What affects sperm health
Heat. The testes function below core body temperature. Prolonged laptop use on the lap, frequent hot tubs and saunas, and occupational heat exposure are worth reducing.
Testosterone and anabolic steroids. The most damaging avoidable exposure — they suppress sperm production and can cause azoospermia. Gym supplements are a recognised hidden source.
Smoking, heavy alcohol, cannabis.
Medications — several affect production. Do not stop prescribed medication on your own; ask about alternatives.
Recent fever. A significant illness can affect production for a cycle or two. Mention it if a test follows one.
Age. Paternal age is associated with declining parameters and increased DNA fragmentation — gradual rather than a cliff.
What matters less than claimed
Underwear type, moderate cycling and phones in pockets are frequently cited with weak evidence. Focus on the items above.
On supplements
A Cochrane review of 90 randomised trials in 10,303 subfertile men found a possible increase in live birth that disappeared when poor-quality studies were excluded. The authors rated the evidence very low certainty and inconclusive, and found insufficient evidence for any specific antioxidant or dose.
Low risk, low cost, probably little benefit — and no substitute for assessment.
Three months
Sperm production takes roughly 72 to 90 days. Any change needs that long before a repeat test reflects it. Most people expect faster results and stop too early.
Sources
- WHO laboratory manual, 6th edition (2021)
Frequently Asked Questions
What is a normal sperm count for fertility?▾
Per WHO 2021 guidelines, a normal sperm concentration is ≥16 million per mL, or ≥39 million sperm per ejaculate. However, sperm count is only one factor — motility, morphology, and DNA integrity also matter significantly for fertility.
Can a man with zero sperm count (azoospermia) father a child?▾
Yes, in many cases. Obstructive azoospermia (where sperm are produced but cannot exit) allows sperm retrieval via PESA or TESE with very high success rates. Non-obstructive azoospermia is more challenging, but micro-TESE retrieves sperm in approximately 50% of cases, which is then used for ICSI.
How long does it take to improve sperm quality?▾
Spermatogenesis (sperm production) takes 72–74 days. Any lifestyle change or treatment will take at least 3 months to show improvement in semen parameters. Antioxidant supplementation, quitting smoking, and reducing heat exposure are the most evidence-based approaches.
Is ICSI always needed for male factor infertility?▾
Not always. Mild oligospermia or asthenospermia may respond to IUI (intrauterine insemination) if sperm counts are sufficient (>5–10 million total motile sperm). ICSI is recommended for severe oligospermia (<5M/mL), azoospermia requiring surgical retrieval, or failed IVF fertilisation.