I want to freeze my eggs for future use. How does this work?
The process of preserving eggs for future use is called cryopreservation. While some fertility centers are seeing a trend of women asking about this service to counter the effects of aging, freezing eggs for future use is usually considered for a woman who is about to undergo treatment with chemotherapy, radiation, or oophorectomy (surgery that removes the ovaries). In many cases chemotherapy or radiation can damage a woman's eggs, making it impossible for her to conceive after treatment is completed.
According to Dr. Nora Miller, of The Women's Fertility Center of Stamford, Connecticut, there are a few paths a woman in this situation can take. The first is to have her eggs harvested (after ovulation enhancement with a drug such as Clomid) and frozen for future use. However, she says, "A woman's eggs can be quite fragile and [may] not tolerate the freezing process very well." Eggs have a high water content. Freezing this water (making ice) can affect the eggs' outer covering and lead to problems during thawing. There are different techniques used to achieve success with cryopreservation, including removing some of the water before freezing.
Another option Dr. Miller recommends is to remove eggs and also obtain sperm from the woman's partner to be used for in vitro fertilization, and then storing the embryos for future implantation. This works well if you are in a long-term, committed relationship; however, for a younger woman who may not have a partner at the time, it can pose a bit of a dilemma. Dr. Miller says that she encourages a woman in this situation to consider using donor sperm to help create the embryos. This would involve a future partner's willingness to parent a child who is not genetically his, so it will take some thought and consideration.
The eggs are stored in containers of liquid nitrogen until they are needed. There is no known "expiration date" for frozen eggs, as long as conditions are optimal at the storage facility. Obviously, a woman's physical state will need to be monitored to make sure she does not wait too long to use them.
If you are about to undergo any of these egg-endangering treatments, do your homework and talk to the physicians overseeing your care, particularly your OB-GYN, as well as a good infertility specialist (fertility centers are usually the best bet for this procedure as they have the most experience). They will help you make the best choice to maximize your chances of having a baby.