A pure suspension of sperm is then added to the eggs. Each egg is inseminated with 50,000-100,000 motile spermatozoa. We are now able to treat cases where only a few sperm are in the ejaculate. There were initial concerns that ICSI may increase the incidence of birth defects. It will take more births to narrow the interval further.
Most birth defects appear to be minor, correctable by plastic surgical procedures.
IVF has been around since 1978 and we know that it does not increase the incidence of birth defects. Embryo freezing has been available since 1985 and it is known that freezing does not increase the incidence of birth defects. The day following the retrieval we can examine the oocytes for evidence of fertilization. If there are an excess number of embryos, a decision can be made regarding cryopreservation or freezing. Generally speaking, in a woman under the age of 35, it would be considered appropriate to transfer up to 2-3 embryos.