When we we consider infertility, there are both female and male problems and causes. This the truth that all scientific sources confirm. Additionally, sometimes the cause of infertility lies on both sides and other times it is unknown. So surely infertility is not only a female problem, as it was still believed not so long ago. Eliza Filipiak – embryologist, biologist, biotechnologist representing Salve Medica explains here what techniques can be used to make sure the best sperm is used for fertilisation.
She starts with listing all the diagnostic tools that are used for male infertility, such as general semen analysis, sperm antibodies test, hyaluronan binding assay (HBA), chromatin dispersion test or oxidative stress measurement. Apart from semen testing, it is also possible to diagnose infertility using genetic testing, hormonal testing or early embryo development observation.
Eliza Filipiak stresses that Assisted Reproductive technology (ART) can be used for different reasons. It is implemented to help patients have a baby when other treatment had failed or is simply impossible. Generally, the artificial fertilisation process should mimic nature as long as possible. However, in some cases, the interference with the fertilisation process is so significant (like e.g. in case of ICSI – Intracytoplasmic Sperm Injection) that it is unlikely to let nature decide.
In natural pregnancies, it is the ovum and sperm interaction that decides about choosing the best sperm. When artificial methods are used, this huge responsibility is in the embryologists’ hands. But how do embryologists know which sperm should be chosen for fertilisation? Eliza explains this complicated yet fascinating process.
First of all, embryologists may not always be correct in their thinking. However, they are employing some techniques to make it more correct. If they have the choice, they always choose the motile sperm. The decision on which sperm is the best may be additionally facilitated. Generally, embryologists use two techniques for choosing the best sperm. The first one is non-apoptotic sperm selection. Apoptosis is in other words, a planned cell death. Using a metaphor, it is our body that decides which cell are going to be ‘sent to death’. It refers to sperm as well. In the ejaculate, when the testis work correctly, we have millions of sperm every day. However, it is impossible that all of them work correctly. Some of them are simply used and that’s why they are sent for ‘apotheosis’. In ART, sometimes it is impossible to know which sperm is, literally speaking, on its way to apotheosis as it may look the same as the healthy sperm. Fortunately, nowadays embryologists have techniques to distinguish the two groups of sperm. For example, by the use of the magnetic separation they can get rid of apoptotic sperm and use the best one for ICSI.
Eliza Filipiak also explains the other technique which is called PICSI. Here the prefix ‘p’ stands for physiology. pICSI involves pre-selecting of sperm based on whether or not they bind to hyaluronan. If sperm is correct, it has a hyaluronic acid receptor. Hyaluronic acid is present in the cells surrounding the ovum ( the so-called granulosa cells or follicular cells) and the role of the sperm is to bind it. If a sperm has a hyaluronic acid receptor, it means it is correct in a lot of other ways as well: it’s mature, healthy and able to fertilise the egg. That’s why it is so important to choose the hyaluronic acid-binding sperm in order to assure the correct fertilisation by means of ICSI. Of course, this technique is not used with patients who are diagnosed as having 90% of correct sperm.
As Eliza says, embryologists can also help patients with azoospermia (no sperm count in their ejaculate). There are different causes of this condition. Sometimes testis do produce sperm but the vas deferens is obstructed and the sperm are not appearing in the ejaculate. Other times, the sperm is produced in the testis but unfortunately in a very small amount. In both these cases, embryologists can perform TESE (Testicular sperm extraction) which is a testicular puncture to get the sperm directly from the testis and use them for ICSI. However, the sperm released from testis are not motile. They’re getting the ability to move when they are maturing in the epididymis.
Eliza also gives some details on another sperm diagnostic tool which is the observation of early embryo development for the first 5 days after fertilisation (up to the stage of the blastocyst). On the basis of it, embryologists can choose the best embryo to transfer. The way every embryo develops is also influenced by the quality of the sperm used.
In conslusion, Eliza Filipiak admits that the IVF procedure has sometimes not only the therapeutic role. It can also be a diagnostic procedure. After the IVF cycle, embryologists know more about infertility problems a particular couple is struggling with. Sometimes the way from the first IVF to the final successful one is long. It happens that embryologists know the reason of infertility only after the whole in vitro procedure – but not beforehand.
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