As part of our private fertility service we offer egg, sperm and embryo freezing and storage. Our team of renowned fertility experts at the Assisted Conception Unit place the highest importance on patient safety.
At our dedicated storage facility, your eggs and sperm are stored using a cryopreservation technique called vitrification. It allows us to freeze and subsequently thaw your samples for your future use, with almost the same success rates as using fresh samples for up to 10 years. You can also choose to store your embryos after treatment which can be stored for up to 10 years and used in a future frozen embryo transfer (FET) treatment cycle.
Egg freezing – also called oocyte cryopreservation – helps to increase the chance of having a baby at an older age as human egg quality is strongly dependent on a woman’s age. Therefore trying to secure some eggs at a younger age, can enhance the chance of conception later in life when natural chances drop very significantly. This method collects eggs from the ovaries and freezes them unfertilised before being stored for later use.
“There are many reasons why women may choose to freeze their eggs. Some women may feel that it isn’t the right time to start a family, and they’d like to preserve their younger eggs for future use,” says our consultant gynaecologist and subspecialist in reproductive medicine and surgery, Dr Julia Kopeika.
“Others may wish to preserve their eggs due to cancer treatment or radiation therapy. And there can be religious reasons to undergo egg freezing as an alternative to embryo freezing.”
The optimal age range for egg freezing is under 35. However, if you have thought about it at a much later age, we will be happy to assess you and advise what would be the best option for you depending on multiple factors.
You will typically have some tests before the start of the egg-freezing process. These may include:
Egg freezing can be broken down into three stages:
Ovarian stimulation requires you to take synthetic/or naturally extracted hormones which stimulate the ovaries to grow multiple eggs, rather than a single egg per month (as in the natural cycle). This involves taking injected medications such as follicle-stimulating hormones medications that prevent ovulation (the release of a mature egg from the ovary).
During this treatment, you may need blood tests that measure your response to the medications. You will attend to have vaginal/abdominal ultrasound scans to monitor the response and development of follicles (the sacs of fluid in the ovaries in which eggs mature).
This takes place when the follicles are ready, usually after 11 to 16 days, and will be done at a clinic. You will be given a sedative to make you comfortable for the procedure, called ‘transvaginal egg collection”. This is where an ultrasound probe is inserted into the vagina, allowing the follicles to be identified. A needle will then be guided into a follicle via your vagina, and a connected suction device can remove the egg. In some circumstances, this procedure can also be done through your tummy. It’s called “trans-abdominal”. This process can be repeated to remove multiple eggs – research has shown the number of eggs required to have a more optimal chance of live birth is 15 if you have this process under the age of 35.
Egg freezing will be done soon after the unfertilised eggs have been collected. The eggs are cooled to temperatures -198°C, preserving them for future use. Vitrification – a process used to protect tissue from freezing by stopping ice crystals from forming during the freezing process – assists in egg freezing, which is typically more delicate than embryo freezing.
Following the procedure, you will usually be able to resume your everyday activities within a day or two. When you wish to use the frozen eggs, they will be thawed, and fertilised with sperm. They can then be implanted in your uterus or the uterus of a gestational carrier.
Stimulation for egg freezing usually takes about 14 days – this period of time accounts for the egg freezing cycle, which will begin when you start your period and contact your clinic to let them know you are ready to begin treatment. Between 11 and 16 days of hormone injections are usually required.
There are several steps to take prior to the egg-freezing cycle, such as attending an appointment that guides you on administering medication, gaining an understanding of your cycle schedule and signing the required consent forms. How long these steps take to complete will depend on the individual. You may wish to freeze your eggs during the period following an initial appointment, or you may prefer to take more time to plan and consider your options.
“Research suggests that higher pregnancy rates are associated with eggs frozen at younger ages in comparison to older ages. It is understood that the best time to freeze eggs is before the age of 35,” explains Dr Kopeika.
Women under 35 who freeze 10 to 20 eggs have approximately a 75% chance of giving birth to at least one baby. However, we welcome women older than 35 and who are still ovulating to come and see us too. Every patient is unique, and we can explore the best options to help them get pregnant in future.”