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Spermatogenesis (sperm production) takes place in the testes (singular testis), while sperm maturation happens in the epididymis. Normal spermatogenesis is negatively affected by injuries and structural abnormalities of the testes and epididymis, as well as hormonal abnormalities.

That is why a standard male fertility evaluation includes a physical examination and an endocrine (hormonal) evaluation as well as a semen analysis (spermogram).

A semen analysis provides a measure of male fertility based on several parameters of the semen sample (ejaculate). The most important of these parameters are semen volume, sperm concentration, forward sperm motility and sperm morphology.

To confirm any of the diagnosis listed in the table above a minimum of 2 (preferably 3) sperm analyses (spermograms) need to be performed at least 1 months apart.

In ~ 0.5 % of all men the process of spermatogenesis is highly reduced. This condition is known as non-obstructive azoospermia (NOA) (a – no, zoospermia – sperm cells). In such cases sperm cells may be retrieved directly from the testes, using surgical sperm retrieval techniques such as Testicular Sperm Extraction (TESE), followed by IntraCytoplasmic Sperm Injection (ICSI).


One of the most common structural abnormalities of the male reproductive system, diagnosed by physical examination, is varicoceles (~ 15% of all men). In men with varicoceles the small veins in the scrotum are dilated (enlarged) leading to higher than optimal temperature in the scrotum, which negatively impacts spermatogenesis.