Intracytoplasmic sperm injection (ICSI) is a microsurgical technique within the framework of which fertilisation takes place with the injection of a single sperm in an egg. ICSI is effectuated in eggs taken after ovarian stimulation, as it happens in the case of in vitro fertilisation, and has greatly improved the male subfertility due to serious terato-astheno-oligospermia.
For the implementation of ICSI it is necessary to have a single sperm for each egg to be fertilised. Therefore, this technique is appropriate for every man suffering from a serious problem relating to their sperm quality, having provided substantial solution in many cases of subfertile couples that had no chance in the past. If the sperms are viable, even sperm dysfunction can be treated, given that more than 50% of the eggs are normally fertilised, regardless the quality of sperm. Obstructive azoospermia can also be encountered with direct sperm receipt from the testicles while for the generation of embryos have been used even premature sperms.
The success rates of ICSI depend a lot on the preparation of the sperm as well as on the ability of its micromanipulation in the laboratory. ICSI along with IVF, is the most effective way to alleviate male subfertility, with birth percentages amounting to 20-25%.