Definition - 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 than those frozen using traditional slow freezing.
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. 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.
Two safe methods of cell freezing (cryopreservation) have been developed: slow freezing and vitrification. Vitrification is the preferred method in most clinics.
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 substances called cryoprotectants. The cells are then placed in tiny storage containers (straws) 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 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 3-4 hours after warming.