Egg freezing is a breakthrough technology that allows women to freeze and store their eggs indefinitely and without need for sperm. Once a pregnancy is desired, the eggs are thawed, fertilized and placed within the uterus in order to initiate a pregnancy.
In couples with extra embryos after an embryo transfer, these may be cryopreserved (frozen) for future use. Cryopreservation makes future fertility treatment cycles simpler, less expensive, and less invasive than the initial IVF cycle, since a frozen cycle does not require ovarian stimulation or egg retrieval. Once frozen, embryos may be stored for many years. Couples should decide if they are going to cryopreserve extra embryos before undergoing IVF.
There are several groups of women who are candidates for egg freezing:
A woman wishing to freeze her eggs must take a type of medication called gonadotropins. This medication stimulates the ovaries to produce several eggs or more. These eggs are then collected from her ovaries using a minor surgical technique known as transvaginal oocyte retrieval. This procedure is performed under light anesthesia, and no incision is required. Eggs are then rapidly cooled and frozen in liquid nitrogen for long term storage.
Vitrification comes from the Latin meaning "to turn into glass." It is the process by which eggs are rapidly cooled at a rapid rate. This rapid cooling prevents the formation of ice crystals within the egg. Ice crystals need to be avoided as they often damage the egg when it is subsequently thawed. The resulting frozen egg looks glass-like, hence the term "vitrification."
There is no evidence of an increase in risk to a baby that results from an egg that was previously frozen. While this technology is relatively new, recent studies have been reassuring. In one study of 200 children born following egg freezing, the rate of birth defects (3.5%) was no higher than the rate found in the general population.
In Illinois, many insurance policies cover fertility treatments. Unfortunately, egg freezing is generally not covered. A typical cycle costs approximately $7000. There are additional fees for medication costs and long-term egg storage fees.
Once the eggs are frozen, they are essentially in a state of "suspended animation." They do not age. As far as we know, there is no limit to the length of times eggs may remain in storage and still be viable.
Fertility begins to decline in the late 20's. This decline is relatively slow until approximately age 35. By age 38, the rate of fertility loss begins to accelerate, and continues to do so until the mid 40's, when the chance of pregnancy declines significantly.
Frozen eggs are suspended at the age of the woman at the time the eggs were removed and preserved. The risk of birth defects such as Downs Syndrome increase as a woman ages. Freezing eggs allows a woman to "put the brakes" on the risk of such birth defects. The eggs, in essence, do not age. They remain at the age that the woman was at the time of their removal from her body. While a woman may return years later to use her frozen eggs, there will be no increase in risk to the resulting baby, as these eggs have been "suspended" at that younger age.