In natural fertilization, the selection of the best sperm takes place spontaneously - the egg envelope is a barrier that is a touchstone for the sperm. In the ICSI method, however, we bypass this natural barrier and therefore try to replace the selection of the best sperm with a selection in the laboratory.
To find the best sperm, this method uses a special microscope that can magnify the image of the sperm up to 6000 times. The embryologist looks for sperm that are structurally healthy - they have a long flagellum, there are no visible defects in the head and the head and neck are correctly shaped.
The method is used if the man has a history of abnormally shaped sperm, couples who have repeatedly failed the ICSI method or had unexplained miscarriages.
The embryologist will examine the sperm under a microscope and select the most suitable ones. These are used to fertilise the egg or frozen for future use.
