Intra cytoplasmic sperm injection is usually referred to as micro manipulation, and is a useful method to treat severe male factor infertility.
In this procedure the single sperm is injected into an egg. Then the fertilized embryo is transferred to the woman’s uterus. This procedure is mainly effective for men who have a very poor sperm count.
In patients suffering from obstructive Azoospermia, sperms can be obtained directly from the testes by doing an epididymal sperm aspiration or biopsy and the sperms can be used for fertilizing the oocytes.
In ICSI, the entire process is the same as IVF till egg collection. Once the eggs are retrieved, the sperm is directly injected into the egg.