Jennifer Aniston is not the only woman who has ever considered putting her eggs on ice. In the last twenty-some years since its creation, egg freezing, or oocyte preservation, has soared among reproductive-aged women. The reasons -- not at all Anistonian, like the tabloids would have you believe.
Egg freezing, trailing a good 30 years behind sperm freezing, was originally created as a means of preserving fertility in female patients undergoing chemotherapy or radiation for various cancers. Once the science solidified and infertility doctors started seeing more reliable results, patient lists expanded to include all women who desired delayed, preserved fertility and who could foot the rather extreme bill.
Today, egg freezing is used in a number of different cases, from cancer related ovarian preservation to delayed motherhood for non-medical reasons.
While the procedure itself is fairly straightforward (involving hormone treatment to reset and then stimulate ovarian function for egg retrieval through a non-invasive vaginal procedure), the costs can be quite concerning. Treatment facilities may vary on both the cost of the work-up and egg retrieval, and on the annual storage fees for frozen eggs. A general estimate might range from $12,000 to $20,000, and then a few hundred dollars more per year for egg storage.
Also, as the American Society for Reproductive Medicine (ASRM) points out, oocyte cryopreservation is not an established medical treatment. Every facility's success rates for achieved pregnancy after oocyte thawing differ and depend on a number of factors, like egg quality and stage of maturation.
In general however, the ASRM quotes two different success rates depending on the type of egg freezing procedure performed: a two percent live birth rate per oocyte thawed for the slow-freeze process (more common) and a four-percent live birth rate per oocyte thawed for the vitrification process (newer and with flash freezing).
These low success rates have less to do with the actual freezing part; embryologists have that down pretty well. The main problem comes when it's time to thaw the eggs. In the past especially, eggs had a difficult time surviving this process because water inside crystallized and compromised the integrity of the cell.
Now eggs are frozen only after this water is removed (dehydrating the egg so to say) and a cryoprotectant is inserted in its place (think of it as anti-freeze for your eggs).
Such modern advances in cryopreservation are making this form of assisted reproductive technology more promising than ever. Just a few months ago, the ASRM backed a growing belief within the infertility research community that oocyte cryopreservation holds great promise for fertility preservation overall. They also noted however, that this is a budding science--one that will no doubt require far more research, and one that should be used electively for patients, with all risks and limitations disclosed upfront.
1. Essential elements of informed consent for elective oocyte preservation: a practice committee opinion. American Society for Reproductive Medicine. Fertility and Sterility. Volume 90, Suppl 3, November 2008.
2. Ovarian tissue and oocyte cryopreservation. American Society for Reproductive Medicine Practice Committee. Fertility and Sterility. Volume 90, Suppl 3, November 2008.