Cryopreservation of embryos (the process of freezing, storing and defrosting of embryos) can increase the birth rate, allowing excess embryos that are not used for the current embryo transfer, to be stored for future use.
Embryo freezing / freezing can be done when the embryo transfer cannot be done for the following reasons:
How to do it
Embryos are placed in vessels or vials containing cryoprotective solutions. These are transferred to a programmable biological freezer, which is used to obtain a low, controllable frost rate. During cooling, the cells become dehydrated and, as the temperature drops, more life forms and water are gradually removed from the cells. Slow cooling is continued to -35 degrees Celsius, at which point the embryos are rapidly cooled by rapid immersion in liquid nitrogen (-196 degrees Celsius). Embryos are stored in liquid nitrogen storage tanks until defrosting occurs.