By Karen Buckingham, Repromed Fertility Doctor
Should I freeze my eggs or not? Today, we are becoming increasingly aware that this could be a reassuring option but egg freezing is a decision that requires careful consideration and realistic expectations. Here you’ll find a detailed overview of the pros and cons and some insight into the likelihood of achieving a future successful pregnancy.
There are two reasons you may choose to freeze eggs. The first is in the situation where you may be faced with undergoing a procedure that can affect your egg number or quality. The second is when you wish to preserve your eggs against the age-related decline in fertility that naturally occurs.
For everyone, there is a decline in the quality of both eggs and sperm as we get older. However, unlike sperm which are produced by the millions every day, the total number of eggs you have in your lifetime is set at birth. The difference between sperm production and egg production is that your eggs are at their most fertile when you are in your mid-twenties, but by the time you are mid-thirty the number of high quality eggs will have reduced by half.
Egg freezing may be seen as a promising option if you’re either not in a relationship or perhaps feel you’re 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 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 three to five days until the embryo can be transferred into the uterus or refrozen for future transfer attempts.
How many eggs do I 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.
The following graph 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 have more than a 95% survival rate).
- Not every thawed egg will fertilise normally when injected with sperm – the sperm quality of the future 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 your age at the time of egg collection. The younger you are, the more likely you are to have an ongoing pregnancy.
However, other pregnancy complications such as pre-eclampsia and gestational diabetes 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 be 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 ($7,480 plus medication costs of around $3,570 – $5,650 for the first cycle) and then the future thawing, insemination with sperm and embryo transfer to the uterus ($7,535 plus medication). Costs are as of August 2022.
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. You can find more information on our Costs page.
In summary, advances in technology in recent years have meant that egg freezing is now a possibility to offer you choices about your plans for childbearing. But it should be emphasised 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.
How can I get more information?
We are passionate about offering genuine fertility care and 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.
We are here to help with any queries you may have about egg freezing. If you are a new client and wish to discuss if elective egg freezing is suitable for you, we offer a free 15 minute phone consultation with a fertility doctor. Take the first step today.