Egg freezing

You may be single or in a relationship but perhaps not sure that you want to start a family as this moment or indeed ever. Perhaps you have a medical or surgical problem which may threaten your fertility – ranging from cancer through to a family history of periods stopping early or other conditions that require medication that may alter the function of your ovaries. You may be transitioning and want to freeze eggs before undergoing surgery or hormonal treatment affecting your fertility. 

Which clinic should I choose?

Virtually any clinic with a licence can offer this form of treatment but the techniques involved are different from routine fertility treatments. The skill of your team will contribute to the potential success of treatment if you use your eggs in the future. 

Speak to as many clinics as you can before deciding which clinic to go to. This usually gives you a good indication as to the level of service and the feel of the clinic and team. Most clinics offer a patient information evening and some will offer a personalised tour of the clinic if you want to find a clinic quickly. 

Find out if your clinic offer investigations before or during your consultation which can cut down on the visits required to clinic.

If you have had previous investigations let your clinic have copies as this may prevent the need to repeat some tests

What age should I be when I freeze my eggs?

The success of egg freezing is related to the age at which eggs are frozen. Generally the success rates with egg freezing start to fall after the age of 34 and therefore ideally it is good to freeze eggs before this time in your late twenties or early thirties. However the actual age at which you freeze eggs may well be related to factors you can’t predict  – relationship break ups, medical and surgical issues, gender issues. It is really important to talk to your doctor about the chances of success with treatment

What is ovarian reserve testing?

You will frequently see this term referred to in fertility clinics. This is the capacity for your ovaries to respond to stimulatory drugs and is generally measured with hormonal testing (particularly AMH – anti-Mullerian hormone testing) and an internal ultrasound scan looking at the ovaries and specifically the number of small follicles in each ovary – known as antral follicles. In general the higher the AMH and total number of antral follicles the higher the expectation that the ovaries could respond to stimulation. 

Does this tell me about my natural fertility?

Your ovarian reserve has little bearing on your ability to conceive naturally and cannot be used as a marker of this. 

Generally the tests performed for egg freezing do not tell us anything about whether your tubes (fallopian tubes) are open or damaged. And of course another important factor in terms of pregnancy is the sperm count of your partner (if you have one) or donor sperm parameters. Ovarian reserve testing is only used as a marker of response in assisted conception treatments such as IVF and egg freezing.

Does anything change my ovarian reserve?

Ovarian reserve will get lower with age – this is a natural biological process. In addition to this smoking is known to affect ovarian reserve. Whilst it is possible to undergo egg freezing if you smoke the outcome you may gain from treatment may not be as good.

In addition some contraceptives such as the Pill and some coils such as the Mirena coil, can lower ovarian reserve. Depending upon how urgent egg freezing is it may be sensible to repeat ovarian reserve testing a few months after stopping or removing devices. 

Some studies suggest up to 20% decrease in ovarian reserve with contraceptives.

Currently there are no medications known which can improve ovarian reserve.

Do I need to do anything special lifestyle wise ahead of egg freezing?

Before going through egg freezing your doctor will make an assessment as to your general health. Your BMI is important as the process usually involves some sedative drugs through your veins. If your BMI is high (35 or over) you may need to lose weight before going through this process.

There are no specific dietary requirements ahead of treatment but wherever possible be as healthy as you can – eat a varied diet, try to do some regular exercise and although you can drink when doing egg freezing it is sensible to have no more than the recommended daily amount and not to have alcohol in the days immediately before and after egg collection

What does treatment involve?

Your clinic will devise a specific protocol for you. One of the more common protocols, called the antagonist protocol, involves starting injections of a hormone called FSH (follicle stimulating hormone) on day 2 or 3 of a cycle. After around 5 days of injections a second injection of a medication is introduced (known as an antagonist) which prevents release of eggs ahead of collection. Once sufficient follicles of large enough size are reached then a final injection called a trigger injection is used approximately 36 hours before egg collection. This enables the eggs to make their final divisions so that they can be collected. Collection is normally transvaginal (internal) with ultrasound scan.

During treatment you will normally need anything between 3-5 scans to monitor progress of your follicles. This may alter according to how your ovaries are responding.

How many cycles will I need?

A common misconception is that one cycle of treatment will result in all the eggs you need to freeze. This may sometimes be the case. However the numbers of eggs you need for egg freezing to have a chance of being successful will depend very much on your age and the numbers of eggs you may collect will in turn be related to your ovarian reserve.

It is impossible to absolutely predict what each cycle will yield in terms of eggs 

Some clinic offer packages of treatment at reduced cost so that you can achieve the optimal number of eggs frozen

In general women under the age of 35 are encouraged to freeze between 15-20 eggs to preserve fertility. As we get older the quality of the eggs we produce becomes poorer and therefore more eggs are needed to counteract this. In women over the age of 37 up to 30 eggs may be required to preserve fertility. 

Will treatment be successful if I thaw my eggs in the future?

There are no guarantees of success with egg freezing sadly. However you can increase your chances by trying (wherever possible) to freeze your eggs at a younger age (before 35) and ensuring that you freeze a good number of eggs for your age. With better techniques for freezing and thawing eggs success rates more similar to IVF success rates are being reported by clinics. 

Many clinics run successful egg donation programmes with egg freezing as a technique.

Are all the eggs collected going to be frozen?

Generally only mature eggs are frozen. It is normal for some less mature eggs to be collected from smaller follicles so not all eggs may necessarily be frozen. Usually egg maturity can be assessed a few hours after collection when the eggs are stripped. The egg number you are told from collection may not therefore be the number that are frozen. Ask your clinic to confirm this with you the following day. 

Why do I need to freeze so many eggs?

At all stages of the egg thawing process there is a fall in eggs numbers from one step to the next in the process. The thaw survival rate for eggs is between 80-90%. Of those surviving thaw the fertilisation rate is approximately 60-70%. Of the fertilised eggs remaining approximately 40% may be usable in terms of either transfer of freezing as embryos. It can be seen therefore that starting with 20 eggs may result in 3-4 embryos being produced. 

You must also be aware that occasionally these percentages are lower when it comes to thawing and that it is possible, though far less likely, that no embryos are produced as a result of thawing, 

Are there risks to treatment?

They are 2 different sets of risks in egg freezing, those relating to stimulation of the ovaries and those related to egg collection. Generally the chances of a significant complication with egg collection are less than 1% – these risks are infection, bleeding and damage to the pelvis.

Another condition called ovarian hyperstimulation can occur when the ovaries are stimulated for treatment such as egg freezing. This is a condition which causes sweeling of the abdomen, enlargement of the ovaries and sometimes dehydration with fluid collecting in the pelvis and around some of the major organs.

In the vast majority of cases this is avoidable by using specific protocols and medications with careful monitoring of treatment cycles.

Ensure that you discuss your clinic’s approach to treatment with your clinic so that they can assess whether you are at higher risk of this happening. 

What would I need to do to use my eggs in the future?

The process of preparing for an embryo transfer is easier than the stimulation and egg collection required for egg collection. Usually either estrogen tablets or patches are used to build up the womb lining for approx. 2 weeks. If the lining looks thick enough on ultrasound scan then progesterone (sometimes suppositories and/or injections under the skin) is then used before embryo transfer to synchronise the lining to the age of the embryo generated. This usually means starting progesterone on the day eggs are thawed. These medication then need to be continued until 12 weeks of pregnancy after which time they can be stopped. 

Once eggs have been thawed they are injected with sperm using a process called ICSI (intracytoplasmic sperm injection) as the normal layer of surrounding cells is stripped before freezing to allow rapid colling of the eggs (

How long can I store my eggs?

Currently eggs can be stored for 10 years. If you suffer from premature infertility eg you have had cancer treatment which has stopped your periods, then in some circumstances you may be able to store your eggs for up to 55 years

Are there any additional costs I should know about?

Most clinics will price their treatment cycles differently. It is important to get a costed treatment plan to understand exactly which costs are involved. Remember to ask about medications, screening tests, cost of cycle and continued storage of eggs. Some clinics will offer discounted rates of storage for payment up front for a few years storage.

Do I need to stay in contact with my clinic?

You must let your clinic know if you change address as there may be important paperwork you need to sign to keep your embryos in storage with the clinic

What if I don’t use my eggs?

Only approximately 10% of women freezing their eggs ever use them. This is because some will get pregnant naturally when they find a partner or others may decide they don’t wish to use them. 

It is possible to donate your eggs but you must make your wishes clear on the consent forms you sign at the time of storage or amend your consent forms if it is after this time. If you know you wish to donate your eggs you would need to undergo some additional blood tests at the time of freezing to be able to donate. Talk to your clinic regarding these tests and the costs.

You can also sign consent to donate your eggs to research or training purposes. Again this needs to be specified on your HFEA consent forms.