What Is Embryo Cryopreservation?
What does the embryo cryopreservation process look like?
Embryo cryopreservation literally means the freezing of embryos. It's very important today because we rarely do fresh embryo transfers. We create embryos, freeze them, and then when we're ready we'll thaw that embryo for the transfer.
Why do you need to freeze the embryos?
The reason we freeze all embryos today is because the technology of freezing and thawing of embryos has improved dramatically over the last 10 years. The survival rate of freezing-thawing an embryo is 99%. The pregnancy rates of a thawed frozen embryo compared with fresh are the same in high-quality IVF labs. So cryopreservation through vitrification, rapid freezing, is critical to any high-quality IVF lab today. You want to make sure that the IVF lab that you're using is very skilled and successful at this process. Cryopreservation also allows us to do embryo biopsy for genetic screening. Embryos are cultured to the blastocyst stage, which is a sphere of over 100 cells. Embryo biopsies are performed by removing three to five cells from the outer layer of the embryo and then the embryo is immediately frozen until we're ready to transfer it. It takes about a week to get the genetic testing back. Because the embryo is frozen we wait until we have the results back before it's selected for transfer. Embryo cryopreservation is a big part of what we do today and when you're looking at different IVF programs be sure to ask them about their success rate with freezing and thawing of embryos, it's important!