Vitrification is a great advancement in reproductive technology for preservation of embryos, oocytes and sperms.


Slow-freezing method was used to freeze embryo, sperms and oocyte.  However, the slow freeze process had many problems. Ice crystals were a major issue. Slow freezing led to crystal formation. These crystals broke down the cells.


To help minimise the number of ice crystals, scientists would remove some of the water. But it’s impossible to remove all the water.


With vitrification, the freezing process is so fast that ice crystals don’t have a chance to form. Vitrification has made egg freezing a much more viable option for women.


Vitrification is also being used for embryo, oocyte and sperm cryopreservation. Research is ongoing, but so far, pregnancy rates seem higher with vitrification.


How does it work?


  1. We put the embryos into a preservative called cryoprotectant.
  2. We rapidly cool down the drop of cryoprotectant with the embryo to the temperature of liquid nitrogen – 196 degrees Celsius.
  3. No ice crystals will be created in the protective substance, nor in the embryo.
  4. We store the embryo in the sealed casing in liquid nitrogen.
  5. Before using we quickly warm up the embryo to body temperature and we wash away the preservative.
  6. A transfer to the uterus can happen a few hours later.


Who should consider Vitrification?


  • If the first IVF attempt isn’t successful, you want to have other embryos at hand quickly.
  • If you are planning another child in a few years and do not want to undergo the ovarian stimulation again.
  • You plan the child later, but one of the partners is supposed to go for chemotherapy or radiotherapy and there’s a risk of becoming infertile.