Intracytoplasmic Injection (ICSI)
The first Intracytoplasmic Injection (ICSI) was performed for male infertility due to extremely low sperm counts in 1992. It has been one of the techniques that revolutionized IVF since then. Sperm issues such as low count, low motility or poor morphology (shape) may lead to failure of, or very low levels of fertilization if the eggs and sperm are placed together in a petri dish and the sperm are left to fertilize the eggs. However, ICSI improves fertilization rates significantly in patients with sperm abnormalities. ICSI has revolutionized the treatment of male infertility, making it possible for many men with severe sperm problems to have their own biological children with IVF.
Current sperm tests are a gross evaluation of quantitative properties such as count, movement and shape. There are no functional tests that can determine if a sperm can fertilize the egg in a petri dish. Normal or near normal sperm parameters do not guarantee high fertilization rates. This may result in the waste of invaluable eggs, resources and time. The risk of unexpected low fertilization rates even with apparently normal sperm parameters have led to widespread use of ICSI. In addition, ICSI allows more accurate sampling of the embryos for preimplantation genetic testing (PGT) allowing DNA from only one sperm to be around the egg as opposed to conventional insemination of eggs with hundreds of thousands of sperm.
These advantages have made ICSI the preferred method of egg fertilization for women undergoing IVF.