Advances in Egg Freezing Offer More Possibilities in Fertility Treatment
By Dr. Shunping Wang, formerly with Advanced Reproductive Medicine
The technique of freezing cells or tissues has been widely used in assisted reproduction treatment.
Sperm and embryos can be frozen successfully and both have been part of routine procedures in clinical IVF for a long time. However, freezing eggs, compared to sperm and embryos, has been quite inefficient until recently.
With the introduction and technical improvement of a procedure called vitrification, an ultra-rapid freezing method that avoids the ice crystal formation (which is detrimental during freezing since the ice crystal can break the cell membrane), the ability to freeze and preserve eggs has been greatly improved.
The overall survival, fertilization, and pregnancy rate of frozen eggs is close, or even comparable to frozen embryos, although the success rate varies among patients depending on the quality of the eggs.
Worldwide, it is estimated that there are more than 1,000 live births resulting from egg freezing (also known as egg banking). Recent survey suggests that over 50% of IVF clinics in the United States offer egg freezing to their patients. Many programs offer this service to cancer patients who are facing sterilizing therapies such as chemotherapy or radiation that will negatively impact their chance to have children.
Clinically, egg banking can also be used to rescue the cycle when there are problems with the availability of sperm sample on the day of retrieval. Occasionally male partner has difficulty with sperm collection or inadequate sample at the time of retrieval. In this case, eggs can be frozen for later use when these issues are resolved later.
Another application for egg banking is to provide an alternative choice for young women who wish to delay motherhood and preserve their reproductive potential.
Finally, it can improve the synchronization of donation cycles. In the future, egg freezing may facilitate a more efficient egg donation program and improve cost effectiveness.
The recent advances in egg banking offer new possibilities in fertility preservation for patients in need for medical or social reasons. Egg banking should also have great impact on the egg donation process. The future direction is to further improve the efficiency of egg freezing and to establish standardized protocols among different programs.