Vitrification

vitrification is the process of converting something into a glass-like solid, free of any crystal formation. By adding a cryoprotectant, water can be cooled until it hardens like glass without any ice crystals forming. This is important in the embryology world because ice crystal formation can be very damaging to frozen embryos.

Vitrification in IVF can allow freezing of spare embryos with better post-thaw survival rates and higher pregnancy and live birth rates from frozen embryo transfer cycles. This rapid freezing process is the most effective method of successfully freezing blastocysts.

Blastocysts have a large space in the middle of the embryo that fills with fluid. Embryologists have found that making a tiny hole between two cells permits the fluid to leak out, collapsing the embryo and permitting more effective vitrification. Blastocyst stage embryos are often “collapsed” on purpose before freezing to allow the cryoprotectant agents to infiltrate the cells in the embryo more effectively.