Male factors are the main cause of infertility in a third of cases as well as a contributory element in a further third, so it is recommended that semen analysis is performed early in the investigation.
Semen analysis (SA) is a series of measurements made on the ejaculate, with the results used to make an assessment of male factor infertility or fertility.
In this presentation by Dr Thanos Papathanasiou, Bourn Hall’s Regional Lead Clinician for Anglia, guidance is given to health professionals about how to ‘read’ the results of a semen analysis and how to present this information to patients.
SA requires the production of a fresh sperm sample after a short period of abstinence (3-7 days).
The World Health Organisation (WHO) has been a driving force in regulating and standardising semen analyses and how to report SA.
Still, a standard report includes various semen parameters with reference values and these can be tricky to interpret.
In this video presentation Dr Papathanasiou explains:
The provenance of the test (0:53) – The latest reference values were set by WHO in 2010 and represent the lowest 5% cut-off values of the sperm characteristics of ‘recent fathers’ (men who have achieved natural pregnancy in the last 12 months)
How a test result can be read – There is no single best way of ‘reading’ a SA report. As a rule of thumb, there are 3 semen characteristics which are clinically relevant:
- Amount; as expressed by the total count in the ejaculate or concentration per ml
- Motility; as expressed by the proportion of total motile or progressively motile sperm
- Morphology; as expressed by the proportion of normal forms
What is ‘normal’ (2:33)
How many tests are required (4:38) – There is physiological variation in sperm numbers within the same individual. About 15-20% of men attending fertility clinics will have a low result in their first SA followed by a normal result in the second SA
Different approaches (5:15) – Discussion of the NICE Guidelines for Semen analysis and the Dutch Model
What to tell the patient
The limitations of semen analysis (SA) must be kept in mind when counselling couples, particularly when the results do indicate a potential male problem.
The SA compares the man’s sperm to the sperm of ‘recent fathers’. It does not confirm or refute the ability to achieve natural pregnancy; by definition, 5% of ‘recent fathers’ will have numbers lower than the reference values.
An abnormal SA is informative in that it confirms that a male factor is likely contributing to the couple’s subfertility. This finding may warrant lifestyle improvement interventions or further testing of the male partner to ascertain the best course of treatment.