Intracytoplasmic sperm injection, or ICSI, involves injecting a single live sperm directly into the centre of a human egg. The procedure overcomes many of the barriers to fertilization and allows couples with little hope of achieving successful pregnancy to obtain fertilized embryos.
How is ICSI performed?
There are basically five simple steps to ICSI which include the following:
- The mature egg is held with a specialized pipette.
- A very delicate, sharp, and hollow needle is used to immobilize and pick up a single sperm.
- The needle is then carefully inserted through the shell of the egg and into the cytoplasm of the egg.
- The sperm is injected into the cytoplasm, and the needle is carefully removed.
- The eggs are checked the following day for evidence of normal fertilization.
Who should consider ICSI?
ICSI is considered absolutely necessary is in the case of male factor infertility with an abnormal semen analysis. Male infertility factors can include any of the following:
- Low sperm counts
- Poor motility or movement of the sperm
- Poor sperm quality
- Sperm that lack the ability to penetrate an egg
- Azoospermia --- this is a condition where there is no sperm in the male’s ejaculation. In these cases, sperm may be extracted from testis or epididymis and can be used to fertilize eggs using ICSI technics (See TESA / ICSI)
Also some patients may choose to undergo ICSI for reasons other than male factor infertility, including:
- Previous poor fertilization with IVF
- Unexplained infertility
- Patient going for PGT (Preimplantation Genetic Testing)
What is the difference between ICSI and IVF?
The key difference between IVF and ICSI is how the sperm fertilises the egg. In IVF, the egg and sperm (of which there are multiple) are left in a petri dish to fertilise on their own. In ICSI, one sperm is directly injected into the egg.