ICSI - Intracytoplasmic Sperm Injection

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Overview

ICSI, typically pronounced “eeksee” or “icksy”, is an acronym for “Intracytoplasmic Sperm Injection”. What does this mean? Simply that instead of letting a man’s sperm find and attach itself to a woman’s egg by itself, a single sperm is “injected” into a woman’s egg. ICSI is typically used to combat male infertility, where it may be the case that a low sperm count, or inactive sperm make the fertilization process difficult. The procedure is done outside of the body, and as such requires harvesting of both the woman’s immature ovum (oocyte, or egg cell) and the man’s sperm. After the injection of sperm, the egg is placed into a cell culture and monitored in the lab for several days. Ideally within those several days, signs of fertilization are seen, at which point the egg may be implanted back into the woman for the pregnancy to begin.

IVF vs ICSI

In contrast to ICSI, IVF (In vitro fertilization) is targeted at solving female infertility issues. In the IVF procedure, the egg harvested from a woman’s body is essentially left to sit in a petri dish that contains many thousands of the man’s sperm for several hours up to several days. What this procedure does, is to bring the egg to the sperm. This circumvents female fertility issues such as scarring of the fallopian tubes that may inhibit the sperm from ever reaching the egg. In the petri dish, the sperm can then compete to be the first to enter the egg, fertilizing it. The IVF process also involves several steps before the egg harvesting stage (to produce multiple eggs, more than a normal cycle) and several steps to ensure the female's body is in optimal condition to accept the implantation of the fertilized eggs. For more details on the IVF process refer to our articles on “the stages of IVF”.

Possible ICSI Complications

Apart from some suggestion that there is an increase in birth defects with IVF in general (with ICSI being essentially a method of IVF), there are no indications that ICSI specifically is any more or less prone to causing problems with the pregnancy. However, it is important to consult with your doctor about the latest research and developments.

Sperm Selection

The “natural” method of fertilization competes many thousands of sperm against one another in the quest for being the first to reach and penetrate the woman’s egg. This competition is essentially a means to ensure that the more mature sperm (being the most robust for pregnancy success) are more likely to be those that participate in the pregnancy. One argument against the ICSI procedure was that the sperm is essentially chosen at random by the embryologist (the person doing the injecting) with a pipette from a semen sample. This could lead to selecting an immature sperm, and hence increasing the risks of problems with conception. However, more recent ICSI procedure implements a selection step whereby the semen sample is exposed to a gel whose properties are such that only mature sperm stick to it. Then, the embryologist simply selects from the mature sperm, improving the chances of a successful pregnancy.