A little biology
Ovarian Reserve & Age
A woman’s ‘ovarian reserve’ – the number of eggs she has left in her ovaries – falls with age.
Tests of ovarian reserve can be used to predict the number of eggs you are likely to get in an egg freezing cycle. The most signiﬁcant factor is the woman’s age at the time of egg collection and her ovarian reserve. Your fertility expert will explain this in more detail at your initial consultation.
AMH Test to Measure Ovarian Reserve
The Anti-Mullerian Hormone (AMH) test is the best test currently available to estimate ovarian reserve. It can also be used to indicate the possibility of an earlier than average loss of fertility. For this reason, we oﬀer the AMH est at the ﬁrst consultation with a fertility specialist.
AMH tests do not show who is more fertile than average, nor do they predict ovarian reserve accurately in women with Polycystic Ovaries (PCOS). Your family’s fertility history, your medical history, your current health and lifestyle, and other factors can also help build a comprehensive picture of your fertility – both now and into the future. More about AMH
How many eggs can I expect?
If you’ve never had fertility treatment before, your AMH level is the best predictor of how many eggs to expect from a single cycle of egg freezing. Age is much less important. However, there is still a lot of variation between diﬀerent women with the same AMH level, and from cycle to cycle in the same woman. We’ve shown what to expect in the graph below.
- The middle line shows the average number of eggs suitable for freezing according to the woman’s AMH level.
- The lower line is the 10th centile which means 1 in 10 women will get fewer eggs than indicated.
- The upper line is the 90th centile which means that 1 in 10 women will get more eggs than the upper line.
Watch our informative Egg Freezing video here.
THE PROCESS OF EGG FREEZING - Egg freezing involves all the steps of an IVF cycle, up to and including egg collection.
Initial stage: Egg Freezing
- Treatment starts with ovarian stimulation, which uses medication that mimics the body’s reproductive hormones to increase the number of eggs available. There are a variety of medications used to do this, and they all work similarly. We’ll provide you with an information magazine ‘Pathways to a Child’ that covers all the steps in more detail.
- When the eggs have matured, they are collected by a simple medical procedure, and frozen by a method called vitriﬁcation.
Later stage: Egg Thaw, Fertilisation, and Transfer
- When you want to use the eggs, they are thawed, and the IVF cycle continues.
- We’ll add sperm to the eggs to create embryos, transferring the best resulting embryo to your uterus and freezing any extra embryos.
What are my chances of having a baby?
We can’t give real-world egg freezing success rates for every combination of age and number of eggs simply because it's a relatively new technique. There is not enough data available at Fertility Associates or internationally. However, several experts have calculated the probability based on the number of eggs stored and the age of the woman when she stored her eggs. An example is shown below, using data from a scientiﬁc publication by Doyle and co-authors in the journal Fertility & Sterility.
Boosting your chances:
The graph below shows that two things can increase your odds of having a child:
- If you can, freeze your eggs while you are younger.
- If you can, freeze more eggs. The way to do this is to have more than one egg freezing cycle.
For example (according to the graph):
If you are 36 years, of age then 10 eggs will be needed to give you a 50% chance of having a child.
If you are 39 years of age then 16 eggs will be needed to give you a 50% of having a child.
Handy To Know
- Embryo Freezing - If you have a partner, it may be better to freeze embryos than eggs. This means that the eggs are fertilised with sperm before freezing.
- Sperm Donors - An increasing number of single women are opting for Assisted Reproduction today. Some are looking to have a baby by using a sperm donor and may consider freezing eggs now for donor treatment later. If you are thinking about this, please take into account that there is a wait time to access a clinic-recruited donor. Please ask your medical team for more information.
- Fertility Funding - Storing eggs or embryos prior to cancer treatment, or other medical procedures that impair fertility, may be publicly funded. This is dependent on whether you have already had a child or not. Check with your specialist to find out whether you may be eligible. More here
- How long can I store my eggs? The Human Assisted Reproductive Technology (HART) Act limits storage of sperm, eggs or embryos to a maximum of ten years. However, you can apply to the Ethics Committee if you wish to extend storage before you reach the ten year limit. We can help you do this. We will try to contact you each year to see if you still want to store your eggs or embryos. We may discard material if we cannot contact you after two years. Therefore, it’s important that you keep us updated of any changes to your contact details and address. more