Egg Preservation Through Vitrification

Vitrification is a process by which eggs or embryos can be cryopreserved so that the cells are allowed to stay in a glasslike state. It has really revolutionized cryopreservation for embryos and eggs in that when these cells are frozen, they aren't allowed to develop ice particles, which can be damaging to the cell membranes and make it so that once they're thawed, they don't survive the thaw as well. With vitrification, because there is no opportunity for ice crystal formation, the embryos and the eggs are preserved so well that when they're thawed, it's almost as if they were never cryopreserved in the first place. This is particularly important with oocytes, with eggs. The egg is a large cell, and when you freeze it by what was traditionally what we call a slow freeze process, ice crystals could form and therefore damage the cell. So now with the advent of vitrification, we can freeze eggs, thaw them, and use them as if they were fresh. And embryos, when we freeze them and thaw them, when they come out of the freezer, they are in the same state they were before they were frozen. So for IVF, it's great because cryopreserved embryos can give pregnancy rates that are very similar to the pregnancy rates that we have with fresh embryos. For patients who want to preserve their eggs, for instance, a patient who's going through cancer treatment may want to have their eggs collected so that they're available for them once they're finished with their cancer treatment and they have an opportunity to reproduce. Whereas after cancer treatment, sometimes with some of the powerful chemotherapy medications that they're given, their ovarian function is diminished, their egg quality is diminished. And so by freezing them ahead of time, they have an opportunity to come back and still be able to benefit and hopefully reproduce. One of the other advantages of vitrification and the fact that it gives us the opportunity to freeze eggs and later thaw them and use them very effectively as if they were fresh eggs is that with egg donation cases, there are patients who are older or who may have lost their ovarian function and would like to conceive and need to take advantage of doing in vitro fertilization using donor eggs. It is a cumbersome process that typically entails synchronizing a recipient's cycle with a donor's cycle and stimulating the donor. The coordination that is necessary with synchronizing the donor and the recipient can be very cumbersome. The opportunity to stimulate donors, retrieve their eggs, and then freeze them makes that process much less cumbersome.