VITRIFICATION OR SLOW FREEZING
In the recent years, the process of Freezing eggs or Embryo freezing, called cryopreservation, has been replaced by a process known as vitrification .
Embryos can now be stored better by a new method of freezing, which prevents formation of unwanted ice crystals. This in turn helps with higher survival rate of eggs and embryos.
What is Vitrification ?
The word ‘Vitrum’ in Latin means glass. Vitrification is the process of rapid freezing such that water molecules instead of forming ice crystals, instantly solidify into a structure that appears like glass. Though the process is much more complicated than cryopreservation, it has shown good results. With the formation of ice crystals there were chances of the quality of the frozen cells deteriorating, but with vitrification that is eliminated.
Why consider Vitrification ?
During the course of an IVF cycle, often more than one embryo is produced. In the course of one cycle, the doctor does not use all the embryos at once since this may lead to multiple pregnancies. One embryo is selected for transfer to the uterus while the rest of the embryos can be stored by freezing them using the method of vitrification. In case the couple needs to undergo another cycle of IVF, these stored embryos may be used after thawing them.
It not only saves time but also helps eliminate the painful and complicated process of undergoing egg collection all over again. Vitrification as a process has helped many such couples that have been trying to have a baby by undergoing repeated IVF cycles. Frozen embryos have yielded results equal to fresh embryos and sometimes even better results.
What is the process of Vitrification ?
- The slow freezing method takes a couple of hours to bring the temperature of the cells down to -196° Celsius. This low temperature stops all biological changes or processes in the cells. This method is time consuming and hence the name.
- Whereas vitrification on the other hand, is the exact opposite of slow freezing. The cells are cooled down quickly and transformed into a glassy state. The entire process requires several scientific solutions and equipment and preparation of the process starts a day before.
Can vitrification increase success rates?
- The solid glass formed retains the same ionic and molecular composition as the liquid state. This process, also avoids the formation of any intracellular or extracellular crystals thereby avoiding any damage.
- Since the process does not bring about any kind of physical or chemical changes in the cells, the success rates are equal to newly collected cells.
- Survival rate of the cells are as high as 85% and the rate of success are 65% depending upon the age of the woman.