ICSI – Intracytoplasmic Sperm Injection
ICSI means injection of the sperm into the middle of the egg. ICSI is an effective method to fertilize the egg.
How is ICSI done?
As with IVF, the ovaries are first stimulated by injections and eggs are retrieved.
IVF with ICSI involves the use of specialized micromanipulator and an inverted microscope that enables embryologists to pick up individual sperms in a tiny specially designed hollow ICSI needle. The needle is then carefully advanced through the outer shell of the egg and egg membrane and the sperm is then injected into the inner part (cytoplasm) of the egg.
What percentage of eggs get fertilized after ICSI?
This usually results in normal fertilization in approximately 70-85% of eggs injected with viable sperm.
Who should be treated with ICSI?
Men with very low total motile sperm counts
In couples who have had poor fertilization with IVF in a previous cycle
Men who have no sperms in their ejaculate but need removal from their testes (testicular sperms do not have the capacity to fertilize)
When fewer than 5 eggs have been retrieved – here ICSI is done to more eggs fertilized
When the number of eggs retrieved are less than 5. Here ICSI is used to get a higher percentage of eggs fertilized than with IVF (just mixing eggs and sperm together).
How is ICSI performed?
This is performed with a specialized ICSI microscope
Under the microscope, the egg is held by a special holding pipette
A very fine needle is used to pick up the sperm and immobilize it
The needle with the sperm is introduced carefully through the outer layer of the egg(zonapellucida) and then into the cytoplasm of the egg
The sperm is then injected into the egg gently and the needle carefully removed
The eggs are checked 18 – 20 hours later to see if they are fertilized
Pictures of ICSI – Step 1
Egg has been held in place.
Sperm has been picked up by hollow needle (below X)
ICSI needle is ready to pierce the outer covering (zona)
Needle has penetrated the outer shell (zona) and is stretching the outer membrane.
The sperm is seen at the tip of the needle.
The needle is within the cytoplasm of the egg and the sperm is about to be injected inside
Fertilization is checked 18 hrs later and the embryos are transferred into the uterus on day 2, 3 or 5.