Diminished Ovarian Reserve and Egg Quality: Is There a Correlation?

When it comes to eggs, there are two main factors that define them: Quality and Quantity. Egg quality primarily refers to the genetic makeup of the egg – it can either be genetically normal or abnormal. Egg quantity, also known as ovarian reserve, refers to the number of eggs in your ovaries. The simplest and most accurate way to measure ovarian reserve today is by testing Anti-Müllerian Hormone (AMH) levels through a blood test. AMH is produced by the ovaries, making it a direct reflection of their reserve.

But what exactly does “diminished ovarian reserve” mean?

And does it impact your fertility? Let’s first clarify what ovarian reserve is and how it relates to your biological clock.

What’s true for all women is that both egg quality and quantity decline over time due to natural aging. To illustrate this, let’s use a gumball machine analogy: The white gumballs represent genetically normal eggs, and the blue ones represent genetically abnormal eggs. In a younger woman’s gumball machine, there are more gumballs overall, with a higher proportion of white ones. In an older woman’s machine, the total number of gumballs is lower, and the proportion of blue ones (abnormal eggs) is higher. This shows that over time, women lose both egg quantity and quality.

Egg quantity, as reflected in AMH, can vary widely from one woman to another, even at the same age. Egg quality, however, remains fairly consistent for women of the same age. So, if you’re wondering how your ovarian reserve is doing, AMH is a good place to start. But what does this mean for your fertility?

Does Diminished Ovarian Reserve Impact Natural Conception?

The answer is: Not really. Every month, regardless of whether you have a high or low ovarian reserve, one egg matures and is released for possible fertilization. And egg quality remains the same for all women of the same age, no matter how many eggs they have. A study by Steiner et al. showed that low ovarian reserve does not correlate with reduced fertility. This means that women with varying AMH levels have the same chances of conceiving naturally, depending on their age.

Why Measure Ovarian Reserve at All?

Measuring AMH is particularly useful for those who are considering assisted reproductive technologies like IVF or egg/embryo freezing. It helps fertility specialists predict how many eggs can be retrieved in one stimulation cycle and assess the chances of conceiving with those eggs. This is where diminished ovarian reserve becomes more significant. A lower AMH means fewer eggs can be harvested in each IVF cycle, leading to a lower chance of success.

Is Diminished Ovarian Reserve Linked to Poor Egg Quality?

Good news: No! While a lower ovarian reserve may lead to fewer embryos being created per IVF cycle, a study by Morin et al. found that the ratio of embryos created from the retrieved eggs and the live birth rate per embryo transfer is the same for women of the same age, regardless of ovarian reserve. In other words, egg quality remains consistent for women of the same age, even though the quantity may differ.

In Conclusion...

Whether you’re in the "top 10%" or the "bottom 10%" of egg yield, it’s still possible to create a genetically healthy egg and achieve pregnancy. For many women who want biological children, investing in treatment is worth it – and this is a great conversation to have when you start working with a fertility expert.