Male fertility tests
When a couple is faced with difficulties getting pregnant, there is approximately a 50% chance of the reason for this being a factor in the male partner.
The main cause of fertility issues in men is poor semen quality. Therefore, various parameters in semen need to be analysed in order to determine what the quality of the semen is. Two parameters are particularly important: the concentration or quantity of sperm in semen and their motility. This needs to be adequate in order to ensure that the egg is fertilised.
There are several quick tests available on the market. They are similar to female ovulation tests and they are understood to carefully evaluate semen quality and determine if a man is fertile or not. But are these tests really useful in understanding semen quality?
The answer is absolutely NOT and the reason for this is that they determine what the sperm count is but do not provide any information on motility and other important aspects which are necessary for fertilisation. Therefore, a test may give normal sperm count results (above 15 million per millilitre of semen) when motility is in fact so low that the egg does not get fertilised and, consequently, the female partner does not get pregnant.
How can semen quality be established more adequately?
Using a seminogram, also known as a sperm analysis, the basic analysis carried out on a semen sample in specialist assisted reproduction centres and other laboratories in order to be able to evaluate the quality of said semen based on different parameters.
The World Health Organisation is the organism responsible for establishing the reference values for determining if a semen sample is normal. The latest figures were published in 2010 and are as follows:
- Volume: at least 1.5 millilitres.
- Concentration level: at least 15 million sperm per millilitre of semen.
- Motility: equal to or greater than 32%
- Viability: equal to or greater than 32%
- Morphology: equal to or greater than 4%
When all the values of a semen sample fall within normal levels, the diagnosis is normozoospermic.
It is also important to mention that semen quality can vary throughout the year or alter for a number of reasons: infections, tobacco, etc. It is, therefore, recommendable to carry out at least two seminograms in order to obtain a reliable diagnosis, particularly in those cases in which one of the parameters falls well outside the established limits.
It should be pointed out that a seminogram is the first step but, in the face of certain semen abnormalities, an assisted reproduction specialist can recommend a wide range of tests such as a male hormone analysis, an examination by an urologist, sperm DNA fragmentation and so on, in order to not only determine if semen quality is poor but to also try to determine the cause of such abnormalities.
It has been proven that infertile males have a greater fraction of sperm with ruptures in their DNA and that this can have a negative impact on assisted reproduction technique results since the transmission of the complete DNA molecule from the sperm to the egg is essential in achieving and then making a pregnancy go full term. An increase in the number of sperm with fragmented DNA can be the cause of embryonic arrest, implantation failure and pregnancy loss. The technique which we use in order to determine sperm DNA fragmentation is TUNEL. It consists of measuring damage in the DNA chain using fluorescent molecules.
Another useful diagnosis technique in semen analysis is fluorescence in situ hybridisation (FISH). It facilitates analysis of part of the chromosomal make-up of sperm. More specifically, chromosomes 13, 18, 21, X and Y which mainly have an impact on pregnancy loss and malformations of the foetus. Semen containing a high percentage of chromosomally abnormal sperm can lead to implantation failure, pregnancy loss or even chromosomal abnormalities in children.