Investigations for the man
This section details the methods used to diagnose male subfertility at Waterstone Clinic. Both partners must be investigated because an appropriate plan of management cannot be formulated without considering both male and female factors.
Semen analysis provides vital information on the quantity and quality of sperm within a semen sample. It is essential to carry out semen analysis at the very start of any investigative process. If some parameters are abnormal, the test will be repeated. Ideally we prefer the samples are analysed by the experienced andrologists/embryologists in our laboratory to ensure accurate results.
The semen analysis is carried out to examine the following:
- Sperm count – the number of sperm present in the ejaculate
- Sperm motility – the sperm’s ability to swim
- Sperm morphology – the shape of the sperm
When interpreting results, we refer to the World Health Organisation reference values outlined below.
|Volume:||1.5 ml or more|
|Ph:||7.2 or more|
|Sperm concentration:||15 x 106/ml or more|
|Total sperm no:||39 x 106/ejaculate or more|
|Motility:||40% or more motile|
|Round cells:||No more than 5 x 106/ml|
|MAR test (Immunobead test):||Fewer than 50% motile sperm with adherent particles|
|Morphology:||Greater or equal to 4% normal|
More detailed sperm function tests are not needed as a routine part of the initial investigation.
Screening blood tests (not required routinely)
The following tests may be required where the semen analysis is suboptimal.
DNA fragmentation test
Testing for sperm DNA fragmentation is similar to the regular method of semen analysis at a fertility clinic. A semen sample is obtained and is sent to a sperm DNA fragmentation centre for testing. This is a relatively new and expensive test that examines the DNA of sperm (sperm DNA health) with a view to determining the best treatment method. It has yet to be established as a clinically significant test.
If semen analysis results are abnormal, blood tests may be taken for levels of testosterone, FSH and LH. A raised FSH level may be an indication of testicular failure.
Blood karyotyping is a test which involves looking at the chromosomes of cells. It involves counting the number of chromosomes in a cell or looking for abnormalities in the structure of chromosomes.
Y chromosome microdeletion
An abnormality of the Y chromosome may be the cause of oligospermia or azoospermia. This abnormality is passed from men to their sons, causing their sons to be infertile.
Cystic Fibrosis carrier screening
Cystic fibrosis (CF) is a genetic condition which affects the respiratory system. CF is an inherited disorder which may be passed from parents to their children. The cause of CF is a defect in a gene called the cystic fibrosis transmembrane conductance regulator (CFTR) gene. A person who has only one copy of this altered gene is called a ‘carrier’ and will not have any symptoms of the condition. However if they have a child with a partner who is also a ‘carrier’ there is a 1 in 4 chance that their child will be born with CF. Cystic fibrosis carrier testing tells you your risk of carrying an altered CF gene. It can also tell you your chance of having a child with CF. However it does not tell you if your child will have CF.
CF carrier screening is also important as about two thirds of men who have an abnormal CF gene will also have congenital absence of the vas deferens (a condition where the sperm ducts do not develop properly). Therefore, sperm is not carried from the testicles to become part of semen, resulting in azoospermia.