Egg (Oocyte) freezing is a method of storing a woman’s unfertilized eggs to allow her to try to conceive at a later date, when natural conception may be less likely. It may offer the option of preserving the possibility of fertility for women who are not in a position to become pregnant straight away, or whose fertility is at risk for medical reasons such as needing cancer treatment.

Frozen eggs may be stored for many years without significant deterioration. When the woman is ready to use her eggs, they are thawed and then fertilized with sperm by injection of the sperm into the egg (ICSI). The fertilized egg is then cared for in the laboratory to develop into an embryo, which can then be transferred to the woman’s uterus with the aim of becoming pregnant.

During IVF or ICSI procedures where only one embryo is transferred, good quality embryos can be frozen (the medical term is ‘cryostorage’). Thawed frozen embryos can then be used at a later date if treatment is unsuccessful or if you wish to have further children. Embryo freezing is also a treatment option if you have a medical condition that is likely to affect your fertility or if you have not been able to have an embryo transfer after IVF or ICSI.