In the laboratory: IVF or ICSI
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The sperm is first prepared. The best, most motile sperm cells are selected. |
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Classic IVF |
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Insemination through ICSI: the sperm cell is succed into the needle... |
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...and directly injected into the egg cell. |
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A fertilized egg a day later, still surrounded |
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This is the essence of IVF: the fertilization takes place in the lab instead of in the fallopian tubes of the woman as in nature.
- A few hours after the pick-up, the sperm cells are put with the egg cells and placed in an incubator. The incubator mimics the environment found within a fallopian tube; the same temperature, humidity and atmosphere.
- A day later, they are examined under the microscope to see whether fertilization has taken place. If it has, another day is waited, to see if the embryos continue to develop.
- If this is the case, then their quality is determined and finally on day three or five after IVF, one or two embryos are replaced in the uterus (see embryo transfer).
- It can also happen that the formation of the embryos is less successful and that embryo transfer has to be cancelled. In this case, an appointment with the gynaecologist will be hastily arranged, in order to discuss what went wrong.
Classic IVF
The classic way of performing IVF is as described above, the placing together of the sperm and the egg in a culture dish. If successful, one or more embryos will develop.
Although fresh sperm is preferred for the purposes of IVF, this method can also be performed just as well using thawed sperm which originates from ejaculate. This is the only way of performing the procedure when using
donor sperm.
ICSI
Since the 90's, a new technique has been available to fertilize sperm cells: ICSI (pronounced 'iksi') or intracytoplasmic sperm-injection. This advanced method was developed in UZ Brussel and since then has been implemented world wide.
ICSI is particularly useful when used in couples where the man is less fertile. If his ejaculate contains too few useable sperm for the classic IVF method, then ICSI can be applied. But even if the IVF method doesn't work, ICSI can be used next time, possibly performing both methods on equal numbers of the eggs.
Injection of one sperm into one eggICSI involves the process of injecting every egg cell retrieved at pick-up with one single sperm cell.
Firstly a suitable sperm is selected under the microscope. This is sucked up with an unimaginably thin glass pipette and injected directly into the centre of the egg cell. The pipette penetrates the egg cell and the sperm is expelled into it. The fertilization then takes place mechanically and only one sperm is required.
ICSI is a delicate but highly effective procedure. Of all the eggs collected at pick-up, 80% are generally mature enough to be fertlized in this way. 10% of eggs are lost in the process, but of those which survive the procedure, 70% will develop into embryos.
The result is that approximately 50% of eggs retrieved at pick-up can be used for embryo transfer. With other words, the chance that the woman will be pregnant is just as high as with classic IVF.
no extra risks
Are fertilized egg cells damaged in the process of ICSI? Well, there is nothing to suggest this. There are even less abnormalities apparent in ICSI children, than in classic IVF children.
Moreover, a ripe egg cell is a largely empty structure. The nucleus containing the chromosomes, is located right on the edge, therefore the chance of damage is small.
Strict identification procedures Security is a top priority. During both the fertilization process and the transfer later, (possibly with thawed embryos) strict identification processes are adhered to.
The CRG has
ISO-1589 accreditation. ISO-1589 is an international quality label for healthcare laboratories that establishes strict requirements for the treatment and identification of eggs, sperm cells and embryos.
Since March 2011 the CRG has also used an automated registration system that identifies patients and dishes containing sperm cells, eggs and embryos during the IVF process. When you start treatment, a personal identification card is created for you with a unique electronic reference. That reference is put on special microchip labels that are attached to all dishes and test tubes used to store your sperm cells, eggs and embryos.
When you have your eggs collected, the electronic system ensures that they are gathered in the right Petri dishes. At the laboratory the dishes are automatically recognised and linked to your partner's sperm, so that fertilisation can take place.
When you return to have one or several embryos transferred to the uterus, the system automatically ensures that your fertilised embryos are being used.
With this system the Centrum voor Reproductieve Geneeskunde takes all the necessary precautions to carefully monitor your sperm cells, eggs and embryos during the entire IVF process.
For more information on quality assurance at the IVF lab,
click here.