Intracytoplasmic sperm injection is an ART technique to overcome problems related to male factor Infertility in a couple. Defect in Sperm function is the most important cause of Infertility in a couple related to male factor. 

The procedure of ICSI differs from that of an IVF because the single selected sperm over here is injected by the embryologist whereas in IVF the fertisation takes place in a dish where many sperms are placed near an egg for them to undergo self fertilisation . 

In this procedure the mature egg is held by a special pipette and then a delicate , sharp , hollow needle is used to immobilise it and pick a single Sperm and then the needle is inserted into the ooplasm or egg cytoplasm . After this the hollow needle is carefully removed and these eggs are then examined by the embryologist the next day to confirm the status of normal fertilisation. 

ICSI is recommended to couples when the male partner has a low sperm count , poor sperm motility & or morphology , previous history of failed fertilisation attempts in IVF , or When sperms are collected surgically from testicles or epididymis ( procedures like TESA / PESA / MICRO TESE ) , or when frozen sperms are used in the treatment which are not of optimum quality.