What is ICSI?
ICSI is a method of fertilization that involves the direct injection of a single spermatozoon intracytoplasmically into a mature oocyte.
As a method it was developed to overcome male infertility issues and has been widely applied since 1992 in clinics worldwide. Despite initial concerns regarding its safety, large scale studies have shown there is no danger of ICSI itself on the health of children born as a result of this fertilisation method.
How is it performed?
On the day of egg collection the oocytes are retrieved from the ovaries and are prepared for subsequent injection, by removing their surrounding cumulus cells with the aid of an enzymatic medium called hyaluronidase. The maturity of the oocytes can then be assessed. The sperm sample is also collected and prepared in the laboratory to isolate normal motile spermatozoa.
The ICSI procedure is performed under a microscope with the use of multiple micromanipulation devices. Each mature oocyte is injected with a single spermatozoon. Immature oocytes cannot be utilized. Fertilization is assessed after 16-20 hours. The embryos that develop are monitored for 3-5 or 6 days until embryo replacement to the uterine cavity.
In what cases is ICSI recommended?
The introduction of ICSI has revolutionized treatment of male infertility and there are a number of indications suggesting its use:
- When there is a history of failed fertilization with conventional IVF, even if the semen sample is normal
- If the zona pellucida of the oocytes is thick / hard, especially following oocyte thawing
- When the semen sample is of sub-optimal quality, such as in the following cases:
- Oligozoospermia (low sperm count)
- Asthenozoospermia (low sperm motility)
- Teratozoospermia (abnormal sperm morphology) or combinations of the above conditions
- Azoospermia (no spermatozoa in the ejaculate)
- Sperm agglutination
- When the retrieval of the spermatozoa has been performed through surgical procedures either from the epididymis or the testis (PESA,TESA,TESE,MESA)