What is ICSI?

ICSI - intracytoplasmic sperm injection is a refinement of the IVF technique and offers hope to men with sperm problems.

If a sperm fails to fertilise the egg naturally or during IVF, this is usually because the sperm fails to penetrate the egg’s outer and inner membrane. This is particularly so with men with sperm problems or low sperm production.

With ICSI, eggs are collected from the woman and sperm from the man in exactly the same way as for IVF. The best sperm are selected and a single sperm is injected with a tiny needle directly through the membranes into the egg to achieve fertilisation. If fertilisation occurs, the embryos are transferred as in standard IVF.

ICSI offers hope to couples with an increased risk of fertilisation failure due to low sperm counts or sperm disorders. ICSI also makes it possible to treat severe sperm disorders where sperm is produced in the testes but sperm cells cannot enter the seminal fluid and where there may be a blockage – when the man has undergone a vasectomy, for example. This involves surgical sperm retrieval.

Surgical sperm retrieval

With the introduction of ICSI, it is now possible to treat severe sperm disorders through percutaneous semen aspiration (PESA) and testicular sperm extraction (TESE).

PESA and TESE are used when sperm is produced in the testes but the sperm cells cannot enter the seminal fluid. The vas deferens (the tube which carries sperm from the testes) may be obstructed – in cases where the man has undergone a vasectomy, for example – or absent

With TESE, the sperm is extracted directly from the testis and with PESA it is aspirated from the epididymis. The decision to use TESE or PESA will depend on the diagnosis. In both techniques, the sperm is obtained before the IVF cycle and frozen and injected into the egg using ICSI.