What Does Vitrification Mean?
Vitrification is the technology created to rapidly freeze embryos, sperm, or eggs so that they can be preserved for later use. It involves cooling the cells in such a way that damaging ice crystals do not form.
Embryos frozen by vitrification are found to have better survival rates and are more likely to produce a successful pregnancy.
FertilitySmarts Explains Vitrification
Embryos, sperm, or eggs that are preserved for later use must be frozen in a way that prevents the formation of ice crystals but is also mindful of the toxicity of the chemicals used to accomplish this process. This is because ice crystals are very sharp and can shred the cell membrane, killing the cell. Also, the expansion of water in the freezing process could cause the cell rupture.
Vitrification is the ultra-rapid freezing of cells to prevent the development of crystals. The cells being frozen are placed in a solution to dehydrate them. They must be protected throughout this process using chemicals called cryoprotectants. The cells are then placed in or on tiny labeled storage containers and cooled at the fastest possible rate in liquid nitrogen. This process involves going from room temperature (about 25°C) to -196°C in 2-3 seconds. The entire procedure for 1 embryo takes about 10 minutes.
When the individual or couple who had the embryos, sperm, or eggs frozen are ready to use them, the vitrification process is essentially reversed. The cells are warmed to room temperature, allowed to rehydrate, and then further warmed to 37°C in an incubator. Within 20 minutes, previously frozen embryos are ready for use. Eggs can be injected with sperm a few hours after warming.