ICSI is an acronym for intracytoplasmic sperm injection - which is a fancy way of saying "inject sperm in the middle of the egg". ICSI is a very effective method to fertilize eggs in the IVF lab after they have been retrieved from the female. A common reason used for performing ICSI is for a male factor of the sperm concentrations of less an 15-20 million per milliliter, sperm motility less than 35%, and very poor sperm morphology.
• IVF with ICSI involves the use of specialized micromanipulation tools and equipment and inverted microscopes that enable embryologists to select and pick up individual sperm in a specially designed ICSI needle.
• Then the needle is carefully advanced through the outer shell of the egg and the egg membrane - and the sperm is injected into the inner part (cytoplasm) of the egg.
• This will usually result in normal fertilization in about 75-85% of eggs injected with sperm.
• However, first the woman must be stimulated with medications and have an egg retrieval procedure so we can obtain several eggs for in vitro fertilization and ICSI.
How is ICSI performed?
1. The mature egg is held with a specialized holding pipette.
2. A very delicate, sharp and hollow needle is used to immobilize and pick up a single sperm.
3. This needle is then carefully inserted through the zona (shell of the egg) and in to the center (cytoplasm) of the egg.
4. The sperm is injected in the cytoplasm and the needle is removed.
5. The eggs are checked the next morning for evidence of normal fertilization.
Photos below are an ICSI fertilization procedure in progress.
About to inject the egg with a sperm
Holding pipette on left
ICSI needle on right
Sperm head visible in needle at far right, just below X
Polar body of egg at 7 o'clock
Needle is advanced to the left
Shell of embryo has already been penetrated by needle
Membrane of egg (oolemma) is stretching and is about to break
Sperm head is visible at tip of needle
ICSI needle has penetrated the egg membrane
A single sperm is being injected into the cytoplasm of the egg
