Vitrification is a method for long-term preservation of oocytes or sperm through the rapid cooling of cells. The principle of vitrification is the use of highly concentrated solutions of cryoprotective agents (substances protecting cells from damage from frost) in the freezing medium and subsequent abrupt hypercooling of cells (≥1000°C/min) at below -150 °C.
Why it is good to have one’s eggs frozen?
During a woman’s lifetime, approximately 1-2 million eggs develop in her ovaries, but many of them disappear before puberty. A woman of childbearing age has from 200,000 to 400,000 eggs, and approximately 400 of them will mature. With increasing age, the quality of eggs also decreases, and female infertility after reaching the age of 38 years is common.
Hence, if a woman of childbearing potential is not planning to have a child at the moment, vitrification of eggs may provide a better chance of getting pregnant later in life.
We recommend vitrification in the following cases:
- Before initiation of cancer treatment: chemotherapy may result in irreversible damage to the eggs
- Other health-related reasons: e.g., when ovaries must be removed
- Women of childbearing age who delay having children
Differences between vitrification and cryopreservation
During conventional cryopreservation, lower concentrations of cryoprotective solutions are used, and the cells are frozen very slowly (±0,3°C/min). Although no water crystals are produced inside the cells during this procedure, such crystals are produced in the freezing medium, which can lead to their damage. During vitrification, formation of water crystals is avoided and the success of cell thawing ranges around 95%.