ICSI
Introduction. Intracytoplasmic Sperm Injection (ICSI) is a medically assisted reproduction procedure in which a single sperm is injected into the cytoplasm of an oocyte. There are some differences between IVF and ICSI, however the steps that must be followed before and after insemination are the same. In terms of insemination, ICSI requires only one sperm per oocyte, whereas In Vitro Fertilisation (IVF) requires 50,000-100,000 sperm. Once fertilised, the oocyte becomes a pre-embryo and must be transferred to the uterus to continue its development. The first human pregnancy generated by the ICSI technique was achieved in 1991 by Gianpiero Palermo in Belgium.
Indications. This procedure is most commonly used to overcome male infertility problems, although it can also be used when oocytes cannot easily be penetrated by sperm and occasionally in addition to sperm donation. It is also used in cases of severe teratozoospermia (low percentage of sperm with normal morphology) since once the oocyte is fertilised, the abnormal sperm morphology does not seem to influence the development of the blastocyst or its morphology. In addition, ICSI is used in cases of azoospermia, when no spermatozoa are found in the ejaculated semen, but these can be found in the testis after biopsy.
How it is performed. ICSI is generally performed after vaginal egg retrieval, which allows one or more oocytes to be extracted from the woman's body. In ICSI as well as in IVF, the male partner collects a sperm sample on the same day as the egg retrieval. The sample is checked in the laboratory, and if no sperm are present, they may eventually be extracted from the epididymis or testis. The extraction of spermatozoa from the epididymis is called Percutaneous Epididymal Sperm Aspiration (PESA) and the extraction of spermatozoa from the testis is known as TEsticular Sperm Aspiration (TESA). Depending on the total number of spermatozoa in the semen, either low or high, the semen sample may be washed or capacitated through a swim-up or density gradients.
