Egg Freezing Now Available as Clinical Treatment
We are pleased to announce that the Colorado Center for Reproductive Medicine now has oocyte (or egg) freezing available to patients as a clinical treatment. For the past 20 years, we have been successful at freezing sperm and embryos, but freezing the
oocyte with its chromosomes in metaphase has been problematic.
We now have a method of cryopreservation known as vitrification which has allowed us to achieve high success rates with egg freezing. Vitrification, unlike slow cooling which has been used for freezing over the past 20 years, avoids the damage to the cell invoked by ice crystal formation, as well as the “chilling” effects seen with slow cooling. With vitrification, embryos are taken from room temperature to -196º C in a fraction of a second using high concentrations of cryoprotectants.
At CCRM we performed an initial clinical trial freezing oocytes for patients who desired pregnancy in the near future so that we would be able to thaw those eggs in a short time and determine survival rates, fertilization rates, and pregnancy rates. With this new method of vitrification, we have seen egg survival rates of approximately 80%, fertilization rates of over 80%, and pregnancy rates above 50%. Indeed, these numbers are equivalent to those we achieve with fresh oocytes and suggest that this method of egg freezing will allow patients to preserve their future fertility with great success.
The types of patients who may want to access this technology include young women who want to preserve their fertility due to career or lifestyle choices. Such patients may know that having children will not occur until much later in life and are concerned that their fertility may be compromised at that point. The ability to freeze their oocytes at a young age will give them the opportunity to conceive at a much later age, indeed, well into their 40s.
The second group of patients who are candidates for egg freezing are those young women recently diagnosed with cancer. Since most cancer treatments involve radiation, chemotherapy, or a combination of both, ovarian function is often compromised rendering the patient infertile. If the patient is single, she will most likely not want to fertilize her eggs with donor sperm and freeze embryos.
It would, therefore, be much more desirable to freeze her unfertilized eggs and have the opportunity in the future, once her treatment is completed, to marry and use her partner’s sperm to fertilize her eggs and have children. It is important that the patient be offered egg freezing as soon as possible after her cancer diagnosis so that there is time to proceed with egg collection and freezing prior to the initiation of cancer treatments. In addition, patients with nonmalignant diseases, such as lupus and rheumatoid arthritis, may be on chronic medications that are detrimental to oocyte function. Such patients may also benefit from oocyte cryopreservation.
More information regarding egg freezing can be obtained by setting up a consultation with any of the physicians at CCRM by calling 303.788.8300