New techniques of “micromanipulation” such as ICSI for treatment of these complex cases of male infertility are recommended in cases of severe male factor. This ICSI technique, known as intracytoplasmatic sperm injection, allows us to introduce only one spermatozoon into an oocyte to produce fertilization.
If sperms are not able to fertilize, current technology allows doctors to introduce a spermatozoon into the oocyte. This technology called “intra cytoplasmatic sperm injection” (ICSI) lets an oocyte be inseminated by a sperm retrieved from the sample of semen which has been previously processed in the laboratory, or retrieved by surgery from the epididymis (duct placed at the end of the testicle and transports spermatozoa outside) in the cases of obstructive Azoospermia, or directly from the testicle in the cases of non-obstructive Azoospermia.
In order to do it, it is necessary to remove all the cells surrounding the oocyte, to be able to determine its maturity and then micromanipulate them and therefore introduce the chosen spermatozoon.
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Injection pipet and 6 spermatozoa selected to be injected |
Magnified spermatozoon to observe details of its morphology |
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Mature oocyte (Metaphase II) with Its first polar body: hour 9 |
Recently injected oocyte. It is being held by a holding pipet (left side of the image) and the right side at hour 3 we can see the furrow left by the pipet when it was taken out |
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View of the equipment used to perform the ICSI during the technique |
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If the procedure has been successful it will be seen that some oocytes will show two pronuclei the next morning. At this stage, the oocyte with the sperm inside it is called pronuclear oocyte and it is fertilized.
This will depend on the addition of several facts including the woman’s age, the source of sperm used, morphological quality of oocytes produced, the kind of stimulation and ovarian response, just to mention some of them.
After normal fertilization of oocytes, embryos formation will occur.
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Oocyte normally fertilized with two pronuclei |