Freezing / Vitrification
In cryopreservation, the biological material (eggs, sperm, or embryos) is gradually cooled down to very low temperatures, usually using a controlled freezing process. Once frozen, the material is stored in liquid nitrogen at temperatures around -196°C (-320.8°F). The freezing process can cause the formation of ice crystals, which can potentially damage cells. However, advancements in cryoprotectants (substances that protect cells during freezing) and controlled cooling rates have improved the success of this method.
After IVF, extra embryos can be frozen or vitrified for future use, allowing couples to have another chance at pregnancy without undergoing a full IVF cycle again.
Vitrification is a more advanced form of Freezing that involves rapid cooling of the biological material to very low temperatures, so quickly that ice crystals do not have a chance to form. Instead of forming ice, the material becomes a glass-like solid, known as a vitrified state. This process reduces the risk of cell damage caused by ice crystals. Vitrification is often used for delicate biological materials like eggs and embryos.
Sperm freezing is done for men who want to preserve their fertility before undergoing treatments that might affect sperm quality.