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Assisted Fertilization (ICSI)
ICSI (intracytoplasmic sperm injection) is one of the most significant advances in reproductive technology in many years. Fertilization of the egg in the laboratory during in vitro fertilization (IVF) requires more sperm than one might imagine. Unfortunately, there are many couples in which the husband simply does not have enough active sperm to fertilize the egg. ICSI is designed to eliminate this concern. With ICSI, fertilization can be achieved with literally one sperm per egg. Furthermore, the sperm do not have to look normal (normal morphology). An abnormal, immature or poorly moving (motility) sperm will probably contain a normal compliment of DNA. That is, the genetic package will probably be intact. If there is real concern over this issue, then chromosome analysis can be done on the husband prior to IVF and ICSI. In addition, a test called sperm chromatin structure analysis can be done which tests for the percentage of DNA fragmentation in the sperm prior to IVF with ICSI.
ICSI involves the use of specialized micromanipulation equipment in the IVF laboratory. An egg is stabilized under the microscope with a special micro-pipette. A single sperm is picked up into a second small needle-like instrument and injected directly into the egg. Eighteen to twenty four hours later the egg can be evaluated and then presence or absence of fertilization determined.
One risk of this procedure is damage to the egg. Not all eggs undergoing ICSI will fertilize and not all embryos resulting from this procedure will survive. Several thousand children have been born as the result of ICSI. There does not appear to be an increased risk of any type of congenital anomaly or birth defects as the result of ICSI.
This procedure is useful when there is severe male factor infertility, when there has been failure of fertilization in a prior IVF attempt, or when other testing has suggested a deficit in the fertilizing capacity of the sperm. Also, all frozen eggs that are thawed must undergo ICSI because the cell membrane of the egg becomes somewhat "toughened" and the standard IVF fertilization will not work.
Approximately 65% of eggs inseminated by ICSI will fertilize. Pregnancy rates are virtually identical whether eggs are fertilized by standard insemination techniques or ICSI.
Assisted Hatching
When an embryo develops to the point it is ready to implant in the lining of the uterus, it must hatch out of its protective coating. This coating, or shell, is called the zona pelucida. There is some evidence that the zona may become thickened in some individuals as a result of IVF. If the zona is thickened, it may make it more difficult for the embryo to “hatch out” at the appropriate time. Assisted hatching is another procedure performed in the IVF laboratory using micromanipulation instruments. A very small defect is made in the zona just prior to the embryo transfer. Indications for assisted hatching include women age 38 or older, prior failed IVF procedure(s). and any embryo which on microscope assessment appears to have a thickened zona.
Go to: Risks, Side Effects & Concerns
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