Fertility preservation, more recently known as “Social Egg Freezing / Oocyte cryopreservation” is a feat in modern technological advances which allows women to preserve their most viable eggs through the process of freezing. The intention of the procedure is that in future, the woman may choose to have the eggs thawed, fertilised, and transferred to the uterus as embryos to facilitate a pregnancy.
The procedures success rate (being the chances of a live birth using frozen eggs) varies depending on the age of the woman, and ranges from 14.8% (if the eggs were extracted when the woman was 40) to 31.5% if the eggs were extracted when the woman was 25.
At Lycahealth, we are able to offer a comprehensive Fertility service, from initial consultation through to IVF and Social Egg Freezing. Our services are run by some of London leading Fertility experts, Mr Mike Savvas, Dr Irfana Koita and Professor Charles Kingsland.
The option to freeze your eggs is one that is personal, and requires a lot of thought and support from specialists. However, most commonly the most recurrent reasons are as follows:
Step 1. Before you agree to the freezing and storage of your eggs, your doctor will explain the process involved, including the risks and chance of success. Your clinic should also offer you the opportunity to discuss your feelings and any concerns you may have with a specialist counsellor.
Step 2. You will be screened for infectious diseases, including HIV and Hepatitis B and C.
Step 3. You will have a course of fertility drugs and the development of follicles (fluid filled sacs containing eggs) monitored with ultrasound examinations and blood tests.
Step 4. When the eggs are mature they will be retrieved in an ultrasound guided procedure under light anaesthetic.
Step 5. The eggs are then frozen and stored in liquid nitrogen.
When a woman is ready to become pregnant, her eggs are thawed and then fertilised with the partner’s or a donor’s sperm. If healthy embryos develop, one is transferred to the uterus and any remaining embryos can be frozen for later use.
Biologically, eggs can be stored indefinitely. However it is your responsibility to advise the clinic of any changes to your circumstances specifically relating to where you live and contact details.
The chance of a live birth is similar for vitrified and ‘fresh’ eggs used in IVF treatment. The two most important factors that determine the chance of having a baby from frozen eggs are the woman’s age when the eggs were frozen and the number of eggs that are stored.
The number and quality of the eggs that develop when the ovaries are stimulated decline with increasing age. A woman in her early thirties might have 15-20 eggs available for freezing after the hormone stimulation but for women in their late thirties and early forties the number is usually much lower. Also, as women age they are more likely to have eggs with chromosomal abnormalities.
The number of eggs available for freezing and their quality is important because in every step there is a risk that some are lost. Of the eggs that are retrieved, some may not be suitable for freezing, some may not survive the freezing and thawing processes, and some may not fertilise or develop into normal embryos. Of the embryos that are transferred, only some will result in a pregnancy, and some pregnancies miscarry.
A small proportion of women have an excessive response to the fertility drugs that are used to stimulate the ovaries. In rare cases this causes ovarian hyper-stimulation syndrome (OHSS), a potentially serious condition. Bleeding and infection are very rare complications of the egg retrieval procedure.
Egg freezing is still a relatively new technique and the long-term health of babies born as a result is not known. However, it is reassuring that their health at birth appears to be similar to that of other children.