Traditionally, cells (composed of more than 85% water) were frozen slowly, which generated ice crystals that damaged the cell structure. With vitrification, they are cooled at speeds approaching -23,000 degrees per minute, preventing the formation of crystals and generating a glassy structure that preserves the cell.
Pregnancy rates with vitrified embryos are high and, in some cases, higher than those obtained with fresh embryos in highly complex treatments.