Intracytoplasmic Sperm Injection (ICSI)
ICSI or Intracytoplasmic Sperm Injection. During the traditional IVF procedure, around 50,000 to 100,000 motile sperms are placed for each egg in the media for in vitro fertilization. with the hope that one of the sperm will enter and fertilize the egg by itself. However, with ICSI-IVF, the embryologist takes a single sperm and injects it directly into an egg to increase the chances of fertilization. This happens in situations, wherein the sperm cannot penetrate the outer layer, which could be for a variety of reasons. Either the egg’s outer layer would be thick or too hard to penetrate, or even the sperm would be unable to swim. In such cases, ICSI is done along with in vitro fertilization (IVF) to enable egg fertilization.
How does ICSI work?
There are two ways in which an egg can be fertilized through IVF- the traditional method and ICSI. In the traditional IVF method, more than 50,000 swimming sperm are placed next to the egg in the media in an incubator in the laboratory. When one of the sperm enters into the cytoplasm of the egg the Fertilization occurs.
However, in the case of the ICSI process, a micropipette (a tiny needle), is used to inject a single sperm directly into the center of the egg. With either traditional IVF or ICSI, once the fertilization occurs, the fertilized egg which is now called an embryo grows in the media in the laboratory for some 1 to 5 days, post it is transferred to the woman’s uterus.
When is ICSI required?
ICSI can essentially help overcome multiple fertility issues such when:
- Eggs do not get fertilized by traditional IVF, regardless of sperm condition.
- The In-vitro matured eggs are being used.
- A blockage in the male reproductive tract keeps sperm from getting out. (obstructive azoospermia)
- The male partner produces too few sperm to do artificial insemination (intrauterine insemination [IUI]) or IVF. (Severe oligozoospermia)
- Previously frozen eggs are utilized.
- The sperm may not move in a normal fashion or have trouble attaching to the egg (Asthenozoospermia)
Success rate with ICSI:
It is seen that ICSI fertilizes around 50% to 80% of eggs. However, one may face the following problems during or after the completion of the ICSI process:
- Eggs damage: It may be seen that either some or all of the eggs may be damaged.
- No Growth: The egg might not grow into an embryo even after it gets injected with sperm.
- Embryo growth: The embryo may also stop growing. (growth arrest)
Once the fertilization takes place, a couple’s chances of giving birth to either a single baby, twins, or triplets are the same if they have the treatment with IVF or without ICSI.