Dear Judy, L.A. Times Reporter,I enjoyed reading your article “Health Sense: Success rate elusive on Frozen Eggs ” Health Section LA Times; August 16, 2010, but clarification is definitely needed. Human eggs are fragile whether they are freshly harvested or frozen and thawed. They are large, water filled cells that require a meticulous preparation before freezing and subsequent thawing. Among the limiting rate factors found in older freezing protocols was that they did not sufficiently dehydrate the internal cellular fluid prior to subjecting the egg cell to cooling. Improvements at our center have yielded survival rates of 91% with 86% of thawed eggs progressing to embryos. Between 2005 to 2010, our pregnancy rate has been 53%, showing minimal difference from the standard embryo freezing rates. Techniques such as vitrification, utilize such high and dangerous levels of cryoprotectant solutions, that the egg cannot withstand exposure for more than 60 seconds. The Embryologist processing the eggs has absolutely no margin for error. Some crystal formation is inevitable and may occur in the freezing/thawing phases of both programmed freezing and vitrification techniques. To assume otherwise is less than accurate. It is just a matter of degree that determines if the extent of crystallization is lethal or not. Patient selection is another matter. In vitro fertilization has taught us that nothing replaces young, robust eggs in our quest to achieve high pregnancy rates. It is absurd for patients and fertility clinics to expect high success when the eggs are sub optimal due to age-related deterioration of the internal organelles and the pre-determined cell death known as apoptosis. The annual data published by the Center for Disease Control reveals that the best pregnancy rates are achieved in the 35 years or younger age group. It stands to reason that this subgroup of patients have the best chance for success whether their fresh or frozen eggs are used to achieve pregnancy. Unfortunately for the consumer, the vast majority of clinics offering “egg freezing” have never even attempted to thaw a single one of their patients’ eggs. This is a glaring example of why egg freezing is still considered “experimental.” In the hands of experienced practitioners who practice the art of egg freezing, the success rate in the favorable patient age group approximates those of a fresh IVF cycle. Since it is accepted that the definition of fertility treatments is the birth of a healthy baby, I would be curious to know the live birth rates after egg thawing from the fertility clinics and the experts whom you quoted. In our practice, we have 60 sets of parents of frozen egg babies who would disagree with the content of your article. Like many other areas of medicine, egg freezing and thawing should be left to experienced experts who practice it often and practice it well.
Health Sense: Success rate elusive on frozen eggs
The chances of bringing home a baby after harvesting and preserving a woman’s eggs remain unknown. Often eggs are never retrieved.
August 16, 2010 | By Judy Foreman, Special to the Los Angeles Times
Freezing eggs for non-medical reasons