TABLE 1: World Health Organisation (WHO) reference values for normality of semen characteristics - 2010
VITALITY (% of live spermatozoa) ≥ 58%
MORPHOLOGY (% of normal forms) ≥ 4%
pH ≥ 7.2
MAR TEST (motile spermatozoa with bound particles) <50%
TABLE 2: Specific nomenclature associated with semen quality:
Normozoospermia Total number of spermatozoa within normality parameters.
Oligozoospermia Total number of spermatozoa below the lower reference limits.
Asthenozoospermia Percentage of motile spermatozoa below the lower reference limits.
Teratozoospermia Percentage of morphologically normal spermatozoa below the lower reference limits.
Azoospermia No spermatozoa in the ejaculate.
Oligoasthenoteratozoospermia Number, motility and morphology below the lower reference limits.
Necrozoospermia Low percentage of live spermatozoa in the ejaculate.
Aspermia No ejaculation.

Definitive diagnosis should be established by a sterility specialist.

As indicated in standardised WHO criteria, semen analysis and a guarantee of the validity of testing require:

  • No ejaculation for 2 to 7 days
  • The semen sample to be obtained through masturbation
  • The laboratory to be issued with the sample within one hour of obtaining it

It is worth noting, however, that abnormalities in semen analysis do not necessarily point to a sterility problem. Neither does a normal semen analysis guarantee a man is fertile, as there are other factors (genetic for example) that are not visible in this test and may be the cause of sterility. In such cases, complementary specific tests are required.

Another diagnostic method used is the sperm retrieval test. This involves washing the spermatozoa in order to separate progressive motile spermatozoa from the rest. This makes it possible to evaluate retrieval efficiency and to opt for the most suitable treatment. Standard procedure dictates that if the number of retrieved progressive spermatozoa is equal to or over 3 million, artificial insemination will be possible. If the value is lower, a cycle of in vitro fertilisation should be undertaken.

With the result of these tests it is possible to determine the most probable cause of sterility and draw up a personalised treatment plan.

Some cases, however, require more specific tests with which to complement the sterility test and to explore it in greater depth.