Intra Cytoplasmic Sperm Injection (ICSI)

A revolution for male infertility treatment

ICSI involves injecting a single sperm directly into the cytoplasm of a mature egg (oocyte) using a glass needle (pipette) thus bypassing any barriers to fertilization. ICSI is currently the most successful form of micromanipulative assisted fertilization available for male factor infertility.
 
 
 
 
 

Reasons for ICSI

• » Sperm completely absent from the ejaculate (azoospermia)
• » Sperm present in low concentrations (oligospermia).
• » Poor sperm motility (asthenospermia)
• » Poor sperm morphology (teratospermia)
• » Sperm retrieved by surgical techniques (for example TESA, TESE)
• » Problems with sperm binding to and penetrating the egg
• » Antisperm antibodies
• » Previous failed or poor fertilization
• » Unexplained infertility
• » Frozen sperm limited in quantity
• » If preimplantation genetic diagnosis (PGD) is being used to screen embryos for a specific genetic disorder

The ICSI Procedure

The process is performed on an inverted microscope at a magnification of 200x. The microscope is equipped with a warming stage to maintain a temperature of 37ºC and two micromanipulators moved hydraulically by joystick controllers. Using these tools, precise movements can be made to microtools which hold the oocyte and sperm.

The oocyte is held in place by suction on a holding pipette which is a little smaller in diameter than the oocyte. Sperm are injected using a small sharp injection pipette with an internal diameter of 5 microns, just a little larger than the width of a sperm.
 
A small portion of prepared sperm is added to a solution of polyvinyl pyrollidone which is viscous and slows down forward progression, making individual sperm easier to visualize and aspirate. Morphologically normal sperm are selected for injection, and then immobilized by rubbing the tails with the injection pipette. The immobilized sperm are sucked up into the injection pipette.

Oocytes oriented in such a way as to avoid injection in the area of the nucleus are held in place and a single sperm is injected into each oocyte. Once this is achieved the oocytes are returned to the incubator. Fertilization is assessed the following morning, seventeen to nineteen hours after ICSI.