An IVF cycle produces a number of viable embryos. Those that aren’t immediately transferred back to the patient are placed in cryostorage by lowering their temperature to that of liquid nitrogen (-196°C).
At this temperature, embryos can be stored until they are needed for later transfer. The vitrified embryos can be used in case of repeated cycles and the overall cumulative rate is higher.
It is extremely useful for vitrification of unfertilized eggs, as they contain a high amount of water. Additionally, vitrification is being explored for tissue preservation, as there is thought to be less overall tissue damage from the vitrification process.
Unlike previous slow freeze methods, which took up to two hours to lower the embryo to the correct temperature, vitrification takes just a few minutes, generally less than 1 minute. The embryo is suspended in a very small volume of fluid on the end of a small flat specialised vitrification device. The device with the embryo is lowered onto a metal block that has been cooled by liquid nitrogen where the fluid containing the embryo hardens into a small “glassy” bead.
Benefits of vitrification for doctors:
The vitrification process is both simple and fast;it can be completed in less than 10 minutes.
The prevention of ice crystal formation during the vitrification process successfully eliminates the major factors that can cause cell damage during the slow freezing method.
The process is easy to master: Vitrification involves simply moving the cells between two dilutions, loading them into the vitrificationdevice,and plunging them into liquid nitrogen.
One of the advantages of vitrification is that it allows the operator to observe the cells during the vitrification process. None viable zygotes and blastomeres can be recognized since they do not contract upon placement into the first or the second vitrification solution. The presence of contracted cells during the warming process is a useful marker for cell survival with the exception of oocytes which might survive the vitrification and warming processes, but show degenerative signs approximately 10 to 15 minutes after the warming is completed.
The fact that no special equipment or investments are needed for implementation of the vitrification procedure makes it extremely cost effective,and offers a tremendous economic advantage over traditional methods.
Most IVF clinics are adopting this new technique of embryo freexing because of it’s enormous benefits to both hoapital/ clinics and patients.
It has high embryo survival rates and pregnancy rates.
Useful in case of repeated cycles
Unfertilized eggs which are vitrified have a similar pregnancy rate to fresh eggs , therefore it can be used in preservation of female fertility.