What is ICSI?
Intracytoplasmic sperm injection describes the process whereby a single sperm is isolated and collected and directly injected into a human egg. This technique is often the preferred method to start IVF when male fertility is singled out as the likely cause of an inability to conceive. Low sperm counts or poor sperm motility both reduce the chances of conception. ICSI also helps when a patient has azoospermia, where there is no active sperm in the man’s ejaculations. Sperm may be blocked from a vasectomy, congenital condition, or other health reasons. Chances of obtaining viable sperm due to azoospermia are low.
How is an ICSI performed?
First, a semen sample is collected from which to harvest the sperm. This may be via ejaculation or through needle aspiration. A single sperm is located and harvested under the microscope using a tiny glass pipette. The pipette then penetrates the outer surface of the egg, and the sperm is injected directly into the egg, bypassing the need for the sperm to penetrate the egg’s surface itself. Once the egg is fertilized, the embryo is ready for transfer to the woman’s uterus.
Are there risks involved with the ICSI procedure?
Some studies indicate there may be an increased risk of birth defects associated with artificial insemination in general, and the ICSI procedure, in particular. Imprinting defects are a phenomenon in which genes function differently depending on whether specific chromosomes are passed on by the mother or the father. There is, however, no consensus, with some researchers believing the level of occurrence of imprinting defects is similar to that experienced through natural pregnancy.
Other risks include complications arising from the needle aspiration procedure to obtain sperm, should it be required. The procedure is simple enough and performed under local anesthetic. There is the potential for pain, swelling, or infection of the aspiration site. For the woman, ICSI adds no additional risk beyond those already associated with both preparatory and later stages of IVF treatment. Standard ICSI procedure usually suggests implanting 2 or more embryos, though the transfer of a single embryo may take place when certain quality and patient criteria align.