Cryopreservation (freezing) is a procedure which enables us to store sperm, eggs or embryos in a frozen state at extremely low temperatures. If there are surplus good quality embryos available after the embryo transfer, they can be cryopreserved and then used in subsequent treatment cycles. Cryopreservation can also be used to freeze and store sperm, for example before the start of chemotherapy or when the partner cannot produce a fresh sperm sample for treatment on the day of egg collection.
We use a method of cryopreservation called Vitrification which uses highly concentrated solutions and cryoprotectant to “freeze” eggs and embryos quickly therefore reducing the amount of damage which may occur to them during the process.
During a woman’s lifetime, approximately 1-2 million eggs develop in her ovaries, many of these disappear before puberty. A woman of childbearing age has from 200,000 to 400,000 eggs, and approximately 400 of them will mature and have the potential to fertilise. As a woman’s age increases, the quality of her eggs decrease.
If a woman of childbearing potential is not planning to have a child at the moment, vitrification of the eggs may provide a better chance of getting pregnant later in life.
We recommend vitrification in the following cases:
- Before the initiation of cancer treatment: chemotherapy may result in damage to the eggs
- Other health-related reasons: e.g., when ovaries must be removed
- Women of childbearing age who choose to delay having children