What is ICSI?

ICSI is the acronym for Intracytoplasmic sperm injection, which is the technique that allows a single sperm to be microinjected directly into an egg. This method allows men with very few sperm in their ejaculate to have a chance of reproducing. Prior to ICSI, such men had only the options of adoption or of the use of donor semen! Now, so long as we are able to find sperm in the ejaculate or from the testes, we are able to offer men treatment. We only need one sperm for each egg! It is often argued that ICSI allows us to contravene the laws of nature, since the process of natural selection is bypassed by the method. This is a valid viewpoint, but is tempered by the fact that in the modern age, much of medicine might be accused of the same. This is a matter for philosophers. Since I am only an armchair philosopher, I shall leave it to the experts. When I am in a quandary about such issues, I rely on my ethics committee to keep me on the straight and narrow.

With ICSI we need specialised equipment. The equipment allows us to make highly precise movements when we are manipulating the eggs and sperm. It helps to have steady hands. An ICSI cycle is exactly like an IVF one. The only difference is that after egg collection, instead of just sitting in the incubator waiting for insemination (usually 50 000 sperm per egg is used in IVF), the eggs are treated with an enzyme that removes their jelly covering. This allows the surface of the egg to be subjected to careful scrutiny. This is important, as the injection of immature eggs will not be useful for anyone. ICSI may only be done on mature eggs (Metaphase II stage, for those who might want to know). After all the mature eggs have been identified, ICSI may begin. Sperm for ICSI are prepared using a centrifuge and a special separation medium. Bear in mind that if 10 eggs have been collected, on average, there will be 7 for injection. Each egg is the size of a full stop and each sperm less than one tenth the size of the egg! To be able to carry out ICSI properly necessitates working under a microscope with between x200-400 magnification. The sperm are injected via a glass pipette which is finer than a human hair. Each ICSI takes between 2 to 15 minutes to complete. Once every egg has been injected, they are returned to the incubator. From hereon in, the process is a la IVF. Of the 7 injected we might expect 4 to fertilize, 3 of which might divide. All 3 embryos would be replaced two or three days after egg collection. With ejaculated sperm expect a 10-15% success rate. With sperm aspirated from the testes, 20-25% success rates are possible.

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