Michelle Emblenton, a biochemist at inviTRA, answers this question in the video:
Well, ICSI is part of an IVF treatment. In a classical IVF procedure, the egg cells are placed in the dish and drops of the sperm, previously prepared sperm sample, are added and fertilization occurs naturally. The sperm cell itself must bind to and penetrate the membrane of the egg cell in order to achieve fertilization. With ICSI (intracytoplasmic sperm injection) the fertilization is performed by the embryologists themselves. They select into a micro injection needle the sperm and it is directly inserted into the cytoplasm of the egg cell in order to achieve fertilization. Therefore, ICSI is a more complex procedure and maybe more challenging procedure, requiring greater levels of speciality and is possibly more expensive. Although, nowadays, it is becoming a more and more standardly used practice due to the good success rates that are achieved from it.
