Our labs use the vitrification process to freeze embryos and eggs. Vetrification is currently the state of the art technique for cryopreservation.
Sometimes more embryos are produced in an IVF cycle than can safely be transferred to the uterus because of concerns about multiple births. When this is the case, it may be possible to freeze the extra embryos for use in a future IVF cycle in a process known as cryopreservation. Only embryos that are considered to be viable are frozen or cryopreserved for future use.
Cryopreservation involves gradually freezing embryos in a variety of special media. Embryos can be frozen because of their relatively strong cell membrane, the zona pellucida (glycoprotein coating), that surrounds an embryo and helps to protect the embryo during the cryopreservation process.
The major advantages to using cryopreserved embryos is simplified treatment and reduced infertility treatment costs . The patient only needs to undergo uterine preparation by way of hormone replacement and an embryo transfer to complete a FET. Since the embryos are already available, it is not necessary to undergo a stimulation cycle with fertility drugs and monitoring thus lowering infertility treatment cost.