Intra-Cytoplasmic Sperm Injection (ICSI)

Intra-cytoplasmic sperm injection (ICSI) was introduced in the early 1990’s as a treatment for severe male factor infertility. A single sperm is microscopically injected into the cytoplasm of a mature egg thereby allowing fertilization of that egg. Because only one sperm is needed for each egg, ICSI can be performed in men with very low sperm counts. During a typical IVF cycle multiple eggs are recovered, but they are not all of the same maturity. Only the mature eggs are subjected to the ICSI procedure as these are the only ones that are expected to fertilize. Of the mature eggs that undergo ICSI, approximately 60% will fertilize normally. Therefore it is very important to obtain multiple eggs from the woman in an IVF cycle when ICSI is going to be utilized. Once the eggs have fertilized, their subsequent development and chance for implantation is similar to that of conventional IVF embryos.

ICSI is performed when the man has a very low sperm count, low sperm motility or a high percentage of abnormally shaped sperm (low morphology). ICSI is also performed if there was poor fertilization in a previous standard IVF cycle with normal semen parameters. ICSI is most commonly performed using sperm in the semen ejaculate. However, some men may have no sperm in their ejaculate. In some of these men sperm may be surgically retrieved from the epididymis or the testicle and subsequently used in an IVF/ICSI cycle.

The outcome of babies conceived through the use of ICSI has been the subject of numerous scientific studies. Overall the results are reassuring, however some concerns do exist. It is known that some men have a genetic basis for their low sperm count. Mutations in the Y chromosome have been linked to low sperm counts. These men would not normally father any children due to the severe sperm deficits. However, the ICSI procedure bypasses the natural selection process and allows some of these men to father children. If the low sperm count was due to genetic abnormalities of the Y chromosome, then these abnormalities would be expected to be passed on to male offspring. This indeed has been documented in such cases. Currently, these children are still young and have not reached adulthood. Therefore it is not known if there are other long-term consequences of these genetic abnormalities.

A slight increase in sex chromosome (X and Y) abnormalities has also been reported in infants conceived with the use of ICSI. The risk is estimated to be approximately 0.8%. Although this risk is quite low, it is higher than what would be expected in the general population. It is not clear whether these abnormalities are a result of the ICSI procedure itself or if they simply represent chromosome abnormalities in the father that were passed on to the offspring.

Overall, we feel that ICSI is a very useful procedure that has revolutionized the treatment of male factor infertility. The physicians at Arkansas Fertility & Gynecology will discuss with each IVF patient whether or not ICSI should be performed.