In order for fertilization to occur, there must be enough motile sperm to travel to the egg, bind to it, and penetrate the egg. With mild male factor infertility, intrauterine insemination (IUI) can be performed to improve the chances of fertilization. However, when the sperm count is very low, in vitro fertilization or intracytoplasmic sperm injection (ICSI) must be performed for fertilization to occur.
What is IVF without intracytoplasmic sperm injection (ICSI)?
In the case of conventional IVF, semen is processed to obtain the most mobile, normally shaped sperm. Then many sperm are placed around the eggs in the IVF dish 4 to 6 hours after the egg retrieval. The eggs and sperm are then placed in the incubator for 16 to 18 hours so fertilization can occur. There are strict requirements that the semen must meet in order for conventional IVF to be performed.
What is IVF with intracytoplasmic sperm injection (ICSI)?
If there is any concern that fertilization may occur at a high percentage with this process, then intracytoplasmic sperm injection is performed in order to get as many eggs fertilized as possible. If ICSI is to be performed, the embryologists remove the cumulus cells from around the egg and examine the eggs and determine which ones are mature and ready for fertilization. Only the eggs that are mature will be injected with a sperm. A single sperm is drawn up into a tiny needle and then it is injected into the egg under a microscope. This procedure requires a high level of technical skill. The fertilized eggs are then placed in the incubator for 16 to 18 hours. Intracytoplasmic sperm injection does not guarantee normal fertilization, but it guarantees that each mature egg will have a chance at normal fertilization. Because it requires manipulation of the eggs, ICSI is not performed in every IVF case at Ovation® Fertility.
Intracytoplasmic sperm injection is required if preimplantation genetic diagnosis or screening are being performed as a part of in vitro fertilization. ICSI prevents contamination from additional sperm which would result in errors when the biopsied cells are tested.
See ICSI performed in the laboratory here.