By Karen Buckingham, Repromed Fertility Doctor
Should I freeze my eggs or not? Today, women are becoming increasingly aware that this could be a reassuring option for them but egg freezing is a decision that requires careful consideration and realistic expectations. We thought it would be useful to give a detailed overview of the pros and cons and some insight into the likelihood of achieving a future successful pregnancy.
There are two reasons a woman may choose to freeze their eggs – the first is in the situation where they are faced with undergoing a procedure that may affect their egg number or quality. The second is when they wish to preserve their eggs against the age-related decline in fertility that naturally occurs. Aging decreases fertility in both men and women, but for women, the impact is seen earlier than in men. It is a fact that women are most fertile in their 20s – by the time they reach 35 years of age, the number of viable eggs remaining in their ovaries has reduced by half. Egg freezing may be seen as a promising option for those either not in a relationship or perhaps feel they are not yet ready to start a family.
How is egg freezing carried out?
Egg freezing involves several steps which are similar to a standard IVF cycle. Hormone medications are self-injected for 10-12 days to encourage multiple eggs to mature. During this time, blood tests and ultrasound scans are done to track the growth of the egg-containing follicles. When the follicles are considered to be of a satisfactory size, a ‘trigger’ injection is given to induce the egg maturation process and the eggs are collected from the ovaries, 34-36 hours later. The egg collection process takes around 20-30 mins and is carried out under light sedation and local anaesthesia, requiring a day off work.
The mature eggs are then frozen using a process called vitrification. This whole process from start to finish is around 14 days, but varies as everyone is unique in their response to treatment.
Eggs are technically able to be stored indefinitely without any deterioration, but legally in New Zealand the limit is 10 years. Should you wish to store them beyond this time, an application to the national ethics committee is required.
What happens when I’m ready to try for a family?
In the future, when you are ready to use the eggs, they are thawed and fertilised with sperm from either a male partner or a sperm donor. A single high-quality sperm is selected and injected into the centre of the egg (in a process called ICSI). Those eggs that fertilise normally are then grown in the lab incubator for a further 3-5 days until the embryo can be transferred into the uterus or refrozen for future transfer attempts.
How many eggs do you need to freeze?
This is the big question and is dependent on your age at the time of egg freezing, your ovarian reserve level (also known as AMH level), and your desired family size! As an example, to achieve a 75% chance of having a baby using frozen eggs, a 34 year old woman would need at least 12 mature eggs frozen, whereas a 37 year old woman would need 20 suitable eggs frozen. It’s helpful to understand that one or two egg freezing cycles might be needed to achieve this level of suitable eggs.
See the following graph which estimates the chance of having at least one baby following a future thawing of a woman’s eggs, based on her age at egg collection and number of eggs collected.
There are many milestones that need to be successfully achieved to result in the birth of a healthy baby. A high number of eggs are required to be frozen to give a good chance of pregnancy, this is because:
- Not every egg collected is able to be frozen – they must be both mature and normal in appearance.
- Not every egg when thawed, will survive – the average survival rate is expected to be 80-90% (not as high as freezing embryos – i.e. successfully fertilised eggs – which has more than a 95% survival rate).
- Not every thawed egg will fertilise normally when injected with sperm – the sperm quality of the future male partner is something that is not possible to predict and can definitely impact the outcome of the thaw cycle.
- Not every fertilised egg will successfully develop into an embryo.
- Not every embryo that is transferred to the uterus will result in a baby.
In addition, pregnancy and miscarriage rates are influenced by the age of woman at the time of egg collection. The younger she is, the more likely she is to have an ongoing pregnancy. Other pregnancy complications such as pre-eclampsia and gestational diabetes however, are more influenced by the age of the woman at the time of pregnancy, and so using frozen eggs does not eliminate these risks.
What are the risks of egg freezing?
There are two considerations to make you aware of:
- Risk to you through the egg retrieval process – Like any invasive procedure, the egg retrieval process comes with associated risks of infection, bleeding or damage to surrounding organs like the bowel or bladder, although these risks are very small.
- Risk to the eggs – Vitrification (or rapidly freezing) of eggs is a relatively new procedure and there are currently not a large number of studies to address if there might be any long-term implications from freezing eggs.
How much does it cost?
The total cost of egg freezing will depend on how many treatment cycles are required to obtain the optimal number of eggs. There are two parts to egg freezing – the immediate egg collection and freezing (as at August 2020 this is $6,950 + medication costs of around $3,500 – $4,500 for first cycle) and then the future thawing, insemination with sperm and embryo transfer to the uterus ($7,900 + medications).
As mentioned, more than one egg collection cycle may be required in order to achieve a strong chance of pregnancy. Repromed now offers reduced costs when more than one egg freezing cycle is undertaken. Find more information on our Costs webpage – see section F for egg freezing costs.
In summary, advances in technology in recent years have meant that egg freezing is now a possibility to offer women choices about their plans for childbearing. It should be emphasised however, that this is not a guarantee that the frozen eggs will result in a future baby. For the best chance of having children, if you want a family and are in a position to start trying to conceive, our doctors will likely advise not to delay.
Our fertility clinic is here to help with any queries you may have about egg freezing. We offer ‘fertility excellence with heart’ and are passionate about offering genuine fertility care – our doctors will be transparent with information to ensure you’re clear on the chance of treatment success. It’s our ‘no sugar coating’ promise.
Repromed offer a free 15 minute phone consultation with a fertility doctor. If you wish to discuss with a fertililty doctor if elective egg freezing is suitable for you, please call 0800 483 105 or email to book a consultation.
Prices are current as at August 2020.