Intra-Cytoplasmic Sperm Injection (ICSI)
What is ICSI?
ICSI is a treatment in which one sperm is injected directly into an egg. This technique is performed by an embryologist using very precise instruments and a specialized microscope. The single sperm is selected, isolated and drawn into a micropipette. It is then injected directly through the outer layers of the egg into its core (the cytoplasm). The micropipette is quickly withdrawn and the egg is allowed to fertilize and divide.
In contrast to standard IVF techniques, which rely on the ability of the sperm to bind to and penetrate the egg’s membrane, ICSI eliminates the need for sperm binding and only requires that there be as many live (but not necessarily motile) sperm present as there are mature eggs.
Your doctor may recommend ICSI as part of your IVF treatment to help treat many types of infertility. One common reason for the use of ICSI is if there is a problem with the sperm such as low sperm count, decreased movement or motility or abnormally shaped sperm.
How is ICSI performed?
The eggs are removed from the ovaries by a doctor. If you are using your partner’s sperm, he will be asked to provide a sample through masturbation the same day that the eggs are collected.
Once the eggs and sperm are collected, ICSI will be performed in the lab. Using a sophisticated microscope with state of the art optics, each oocyte is stripped of its surrounding cumulus cells and held in place with a glass micropipette (the “holding” pipette). The embryologist then takes a second, smaller pipette (the “ICSI” pipette) and draws up one sperm from the processed semen sample. The ICSI pipette containing the sperm then pierces the outer zona pellucida and oocyte membrane and, with the aid of fine mechanical controls, the sperm is deposited near the middle of the oocyte. The ICSI pipette is then removed from the oocyte. Some eggs do not survive the ICSI procedure and other eggs do not respond properly and fail to fertilize normally.
After the egg has been injected with the sperm, the embryologist checks the next day to see if the egg was fertilized. If fertilization occurs and the embryo continues to develop over the next few days, it will be transferred into the uterus. Once fertilization has occurred by ICSI, pregnancy rates are similar to those from regular IVF.