Friday, April 13, 2007


One mis-conception (ha ha) that I have noticed about egg retrieval during IVF is the idea that what is frozen afterwards are eggs. Typically, unfertilized eggs are never frozen unless the woman giving the eggs believes she will have a male partner in the future.

The reason that eggs are rarely frozen unless fertilized is that they do not thaw well. The successful thaw rate for fertilized eggs (pre-embryos) is up to 95%, depending on the skill of the embryologist who originally freezes it. Unfertilized eggs which have been frozen rarely become babies when later thawed and fertilized.

It is so rare that a frozen, unfertilized egg can become a baby that the total number of children born from this method worldwide is 200. Compare this to the three MILLION babies born through IVF in the 25 years since the method was first used.

Now a baby has been born from an egg which was frozen, then thawed and fertilized by sperm which had also been frozen. The patient who had her baby this way is Adrienne Domasin. She received free IVF treatment in exchange for being part of the study attempting to achieve a pregnancy from frozen eggs and frozen sperm.

"Egg freezing traditionally has been reserved for women who suffered from illnesses that might leave them infertile and has a low success rate. But there has been recent demand for the procedure by women in their 30s who want to have children in the future but are afraid they will be too old to conceive the traditional way, said Dr. Jane Frederick, who oversaw Domasin's fertility treatment.

The low viability of frozen eggs is due, in part, to ice crystals that can damage the egg's structure, though freezing sperm has been done for decades, said Richard Paulson, a professor of reproductive medicine at USC.

There have been about 200 documented births from frozen eggs worldwide, Paulson said. But he had not heard of other cases of frozen egg/frozen sperm conceptions. The Journal of Assisted Reproduction and Genetics reported one case last year in Australia."