First things first - fertility is complicated and it’s important to remember one key thing:
No test can predict your ability to become pregnant.
When it comes to better understanding your fertility, there are many things to consider and each piece of information gives its own valuable insight. Egg count, or ovarian reserve, is a fundamental fertility marker and it’s one of the first things that a fertility specialist will want to understand when assessing your fertility.
Understanding egg quantity
To conceive naturally, an egg needs to be released during ovulation; that egg then needs to be fertilised by a sperm, and the fertilised egg needs to be implanted into the uterus and begin growing. So, one of the things necessary for a successful pregnancy is having an egg available to fertilise.
We are born with all of the eggs we will ever have, and that number declines as we age. At birth, you are likely to have 1-2 million eggs, but by 25, it could drop to around 300,000 - remember, this is normal. After the mid thirties, the rate of decline picks up speed and continues until you run out of eggs and go through menopause. The thing is that the rate at which egg count drops over the reproductive years can be different for everyone - for some people it happens more slowly and for others more quickly. Egg count (medically referred to as ovarian reserve) is a test that estimates how many eggs you have in your ovaries at a specific time so, when compared to population data, you can find out how you compare to others your age. Knowing your egg count helps identify if you are at risk of running out of eggs early. It also helps inform the timing of your family planning goals and may encourage you to consider the treatment options available to you too.
Considering egg quality
Once you understand your egg count, another equally important thing to think about is egg quality, which refers to the genetic makeup of those eggs. Both egg quantity and egg quality decline with age, but while we can measure egg quantity there isn't a test for egg quality - age is the best predictor. As we age, more eggs are of poor quality which means they have genetic issues that lead to embryos with duplicate copies of chromosomes or missing chromosomes - and poor quality eggs are unable to support a healthy pregnancy1.
Egg quality is typically good in the twenties and early thirties but then generally decreases in most people from the mid-30s onward. From the early 40s, egg quality is usually poor. So you can now see how sometimes having an egg available to be fertilised isn’t enough for a successful pregnancy if the egg is not of good quality - even with help from reproductive treatments like IVF.
Quantity & Quality - no relation
Although egg quantity and egg quality both decline with age, there is no link between them. It’s possible to have lots of poor quality eggs and also possible to have fewer eggs but for them to be of good quality.
If you measure your egg count and are told that you have a good supply of eggs available, that's good news - you are unlikely to run out of eggs early. But please remember, this doesn’t tell you anything about the quality of those eggs.
Your fertility beyond eggs
Egg quality and egg quantity are two key pieces of your fertility picture. But if you have been actively trying to conceive and haven’t been able to, there might be other things that your medical practitioner will want to investigate with you. Ovulation plays a crucial role – if eggs aren't being released from the ovaries monthly then a natural pregnancy can’t happen. It's equally important to ensure the health of both the fallopian tubes and the uterus. Blockages in the fallopian tubes can stop the egg and the sperm from meeting, preventing fertilisation. Additionally, issues with the uterine lining might pose challenges for a fertilised egg to implant and develop into a baby.
As you can see, fertility is complex and requires a lot of things to be working to support a healthy pregnancy.
The big picture
Your egg count is an important consideration in your overall fertility picture and can help you better understand your reproductive health, but it's not the only consideration. Remember, nothing can predict your ability to become pregnant.
DISCLAIMER
If you have any questions or concerns about your health, it is important to discuss them with your healthcare provider. It is important to note that our articles are not intended to replace professional medical advice, diagnosis, or treatment.
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