Male factor
Male factor: what a semen analysis does and does not tell you
Reviewed August 2026 · Jane Ogidigo, Fertilogy™
About half of couples with difficulty conceiving have a male factor contribution, either alone or alongside a female factor. Yet investigation and preparation are frequently organised around the woman, with a single semen analysis standing in for the whole picture.
What a semen analysis measures
A standard analysis assesses volume, concentration, total count, motility, and morphology, against reference values published by the World Health Organization. These reference values describe what is found in men whose partners conceived within a year — they are a population reference, not a pass mark. A result below a threshold does not mean conception is impossible, and a result above it does not guarantee anything.
Variability is normal, and matters
Semen parameters fluctuate considerably in the same man from sample to sample. Illness, fever, abstinence period and the interval since the last sample all influence results. A single abnormal analysis is generally repeated before conclusions are drawn.
What it does not measure
Standard analysis assesses how many sperm there are, how they move and how they look. It does not assess the integrity of the DNA they carry.
DNA fragmentation testing measures breaks in that genetic material. It is not a routine first-line test, and it is not indicated for everyone. It is more often considered where there is unexplained infertility, recurrent pregnancy loss, poor fertilisation or embryo development despite apparently normal parameters, or repeated failed cycles.
Guidance on its clinical usefulness continues to develop and is not uniform between bodies. The right question for your specialist is whether it would change anything in your plan.
Other investigations sometimes indicated
- Hormone testing where the count is very low
- Scrotal ultrasound, for example where a varicocele is suspected
- Genetic testing in severe cases — karyotype and Y chromosome microdeletion
- Referral to a urologist or andrologist, which happens less often than it should
Why preparation takes three months
Sperm production runs on a cycle of approximately two to three months. Anything changed today affects the sample given in roughly three months, not the one given next week. Any preparation shorter than that is unlikely to show up.
What the evidence broadly supports
To discuss with a clinician rather than act on alone: stopping smoking, reducing alcohol, addressing significant overweight, managing heat exposure, and reviewing medications that affect sperm production. Antioxidant supplementation has been studied extensively with mixed and inconsistent results — plausible, but not as settled as it is often sold.
Questions worth asking
- Has the analysis been repeated, and were the two consistent?
- Given our history, is DNA fragmentation testing indicated in our case?
- Would you refer to a urologist or andrologist?
- Does this change whether we use ICSI?
- Is there anything worth doing over the next three months?
Evidence base
This article draws on the following guidelines and sources. Where evidence is contested, that is stated in the text rather than smoothed over.
- WHO laboratory manual for the examination and processing of human semen, 6th edition
- EAU — Guidelines on sexual and reproductive health (male infertility)
- ESHRE — Guideline on unexplained infertility
- ASRM — Committee opinion on the diagnostic evaluation of the infertile male
- Cochrane Database of Systematic Reviews — antioxidants for male subfertility
General information only. Not medical advice, and not a substitute for your fertility specialist.
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