Cryopreservation in simple language means freezing of the embryos. Eggs are fertilized in the IVF(invitro fertilisation)lab with sperm; embryos develop which are then transferred into the uterus. Successful implantation of the embryo following this fertilization process in the IVF lab(invitro fertilisation lab) is an extremely important variable affecting IVF success rates. Optimal success rates usually require an average transfer of two or three embryos. However, it is not unusual for 8, 10 or occasionally more eggs to be retrieved and therefore more than 3 embryos may be produced in an IVF cycle if desired. With the technique of embryo cryopreservation (embryo freezing) embryos developed but not transferred can be cryopreserved and stored for future use. What is the advantage of storing these embryos? There are many advantages of Cryopreservation in IVF(In vitro fertilisation):
Vitrification is a newer technique to freeze embryos. Here, the embryo formed in the IVF(In vitro fertilisation) cycle is coated with a cryoprotectant and rapidly dipped in liquid nitrogen in a much shorter procedure. With the older slow-freeze technique, water, normally found in and between embryo cells, is frozen into ice crystals. As these embryos are thawed for transfer, the crystals can cause damage, which may lead to cell death. With vitrification, water is sealed out and embryos are "warmed," potentially resulting in less damage and hopefully higher pregnancy rates. |