IVF

• Embryo Culture and Transfer
  
• Blastocyst Culture and Transfer
  
• Intracytoplasmic Sperm Transfer ICSI
  
• Cryopreservation of Embryos
  
• Assisted Hatching

In vitro fertilization constitutes the placement of both egg and sperm within the same space, a petri dish outside the body. This is where fertilization occurs. This was first begun as means to bypass the female fallopian tubes for normal fertilization and passage of the subsequent embryo into the uterine cavity. As time passed it has increased in scope to include treatment for endometriosis, for donor egg, donor embryos and gestational surrogates.

During IVF, a woman is given specific medications to stimulate her ovaries to produce multiple eggs. These eggs are then harvested and placed in the embryology laboratory. Three to 4 hours later sperm is placed with the eggs and allowed to fertilize the egg overnight. The following morning they assessed for fertilization. Fertilized zygotes are grown in special culture media for a further 3 or 5 days. Following this period of growth, the resulting embryos are transferred into the wife's uterus, generally on day 3 or day 5 following retrieval. IVF may provide significant information about the cause of infertility by giving direct visualization of female eggs, male sperm, and their subsequent interaction.

Intracytoplasmic Sperm Injection (ICSI)

Intracytoplasmic sperm injection is a specialized form of IVF developed and used to overcome male factor infertility. In this procedure each egg is injected with only one sperm, thereby bypassing the need for the sperm to penetrate the "shell" of the egg to achieve fertilization. ICSI is considered by most to be a safe procedure. However, there are studies showing small but significant increases in non-lethal genetic abnormalities but no increase in birth defects or congenital abnormalities associated with babies conceived via the ICSI procedure. If there is definite evidence of genetic factors being the cause of male factor infertility the ICSI procedure may permit the transfer of these factors. Some of these include the genes that cause the condition known as cystic fibrosis or micro-deletions of the Y chromosome. If this is the case then genetic counseling should be pursued prior to doing ICSI. If the male is carrying the cystic fibrosis genes his wife must also be tested prior to any procedures since the likelihood of having an affected child if both partners are carrying the genes is very high. Affected children may not live long.

Cryopreservation (Freezing) of Embryos

Cryopreservation of embryos is a viable alternative to discarding "extra" embryos not used in a fresh IVF cycle. In this way we can maximize the stimulation of the woman’s ovaries and eliminate the incidence of transferring too many embryos, resulting in a high-order multiple pregnancy.

Cryopreservation of embryos has been available for many years, with the first birth resulting from a thawed embryo in Australia in 1985. Since 1990 there have been increased numbers of these resulting pregnancies, though there is still limited information on long-term effects of cryopreservation. There is no data available to support any increased risks of birth defects resulting from the transfer of cryopreserved embryos. In animal models the use of cryopreserved embryos for over 20 years has not resulted any in birth defects.

During a woman’s natural menstrual cycle only one egg is generally produced each month. With IVF stimulation, the ovaries may produce upwards of 10-20 eggs and with fertilization may result in many more embryos than can be safely returned to her uterus. The use of cryopreservation then affords the couple another opportunity of achieving pregnancy without having the woman undergo the stimulation portion of a cycle. It should be noted that all embryos frozen may not survive the thawing process. As a general rule of thumb, a 50% survival rate may be expected. The more developed the embryo is prior to freezing, the greater its chances are of surviving the thaw. The decision to have embryos cryopreserved requires informed consent. The decision is made by the laboratory staff which embryos are suitable for cryopreservation. Only embryos deemed suitable for freezing and thawing can be cryopreserved. Not all "spare" embryos will meet these criteria.

Laws dealing with cryopreserved embryos are still in their infancy. Our policies with regard to frozen embryos are no different than those in most centers. The frozen embryos are the joint property of the man and woman and any disposition regarding these embryos requires the consent of both parties. Since they are the property of the couple, the couple is free to move them to another site if they desire. Any expenses incurred in the shipment of embryos must be borne by the couple. The embryology lab cannot guarantee the shipment or resultant handling of embryos once they leave this facility.

Assisted Hatching

To easily understand the concept of assisted hatching one must first think of the human egg/embryo as that of a chicken egg, including the "shell". The shell surrounding the embryo is thought to open while in the uterus and allow the embryo to implant in the uterine wall. In assisted hatching, part of this "shell" is opened or removed prior to embryo transfer thereby assisting the embryo in it’s ability to implant and ultimately produce a pregnancy. However, this procedure is not necessary for all patients. Data indicates that assisted hatching is most likely to help in those cases where the "outer shell" of the embryo is thickened.

Any procedures where handling of embryos is involved have associated risks. Embryo damage may occur in spite of meticulous care by our embryology staff. As assisted hatching is one of these procedures, there are risks. For some couples however the benefits of pregnancy may outweigh these risks. Talk to your doctor if you have questions about this procedure.