Male factor: more than a single semen analysis

A semen analysis measures volume, concentration, total count, motility and the morphology of the sperm. It is a useful and necessary test, but it has a limitation that is rarely explained: results from the same man fluctuate considerably between samples, depending on temperature, a recent infection, stress, sleep and the abstinence period. That is why the test is done after two to seven days of abstinence and, when the result falls outside the reference limits, usually repeated after two or three months before conclusions are drawn.

The values in the WHO laboratory manual, sixth edition, published in 2021, are often misread. They are not a boundary between normal and abnormal, but lower percentiles derived from men whose partners conceived within twelve months. A man with values slightly below the limit may conceive naturally, and a man with values inside the limits may have difficulty. The result is therefore always read together with the couple's history and the partner's assessment.

A full evaluation begins with history: how long you have been trying, whether there has been a previous pregnancy, surgery in the groin or on the testis, undescended testis in childhood, infections, illnesses with high fever, medication, chemotherapy or radiotherapy. The physical examination looks for a varicocele, assesses testicular volume and the presence of the vas deferens. Hormones, in particular FSH and testosterone, help to distinguish a problem of production from an obstruction to transport.

In severe cases, where the count is very low or no sperm are found, genetic tests are added, karyotype and Y chromosome microdeletions, along with assessment for cystic fibrosis related mutations. Scrotal ultrasound, and occasionally transrectal ultrasound, completes the picture. This chain is not carried out for every man; it is built step by step, guided by what the previous step showed.

Sperm DNA fragmentation is discussed more and more; at the 2026 ESHRE congress the theme was summed up by the idea that men are more than a basic semen analysis. Even so, the test is not recommended as a routine investigation, and its result should not be the only argument for deciding on ICSI. It can be useful in selected situations, for example after recurrent loss or unsuccessful cycles with no other explanation, and it is always interpreted alongside the rest of the assessment.

Environment and lifestyle have a well-recognised role: prolonged heat, smoking, alcohol, obesity, anabolic steroids and some medicines lower sperm quality. The data on air pollution are newer and should be read as such. A study presented at ESHRE 2026 in more than two thousand men linked exposure to ozone and nitrogen dioxide with changes in sperm DNA methylation, and regional differences in sperm quality in Spain were attributed to environmental factors. These are emerging findings, not proven causes.

Producing a new generation of sperm takes about 74 days, with several more weeks of maturation on top. That is why changes, stopping smoking, losing weight, moving away from sources of heat, stopping anabolic steroids under medical supervision, are reassessed with a new semen analysis after roughly three months rather than three weeks. Some causes have direct treatment: varicocele repair in selected cases, hormonal deficiencies, infections and retrograde ejaculation.

When the count or motility is very low, ICSI allows fertilisation with a small number of sperm. When no sperm are found in the ejaculate, surgical retrieval, TESE or micro-TESE, is discussed after hormonal and genetic assessment. These conversations are emotionally heavy: many men experience the result as a judgement on themselves, speak about it little and rarely seek support. Having the partner present at the consultation and an open conversation about mood are part of care, not an extra.