When the semen contains less than 50 lac sperms per ml, IVF would not be successful. Moreover, if the sperms do not move progressively towards the egg, fertilization will not occur during the IVF procedure. To overcome this situation we resort to ICSI.
The steps of ICSI are more or less similar to IVF, except the process of fertilization.
First, the egg is prepared by removing its outer coat of cells called the cumulus complex.
Second, fertilization is achieved by injecting a single sperm into each egg, with the help of a thin needle.
A device called Micromanipulator is used for the procedure. ICSI is a delicate process, but it is an effective way to improve fertilization rate, and offers hope to patient with severe male factor infertility.
Factors leading to ICSI
Low sperm count in the ejaculate.
Obstructive azospermia (The sperm is present inside the testis. But not in the ejaculate due to blockage in tubules or ducts. The sperms can be aspirated out by a needle and ICSI can be performed.
No motility in the sperms.
Poor or decreased number of normal sperms.
Less number of eggs in women.
Instance of previously failed fertilization.