When you receive your Grip report, we always explain whether your results are within the normal range. But even if your AMH value falls within the normal range, you may be wondering: how does my outcome compare to other women my age?
Before you google where you are on the curve, it is important to know that not every lab uses the same AMH test. There are various 'assays', all of which also give a different result or use a different outcome measure. So you can't just compare yourself with data you find online! In the lab we work with, they use Roche's Elecsys assay.
To better explain this, we have created the graph below. This graph is based on data from a paper by Anckaert et al. (ref 1). In 2015, they conducted a study with 887 healthy women and 149 women who had been diagnosed with PCOS, to determine the normal values for the AMH assay that Grip lab also uses.
Since AMH is not "normally distributed" (like a Bell Curve - think of that math class in the third grade), we can't just take the average AMH to say something about where on the curve your value falls. As you can imagine: your AMH can (in theory!) be unlimitedly high, while there is a very clear lower limit (namely zero, when your ovarian reserve is exhausted). That is why you cannot take the average (which gives too high a value), but we mainly look at the median.
The median is the middle number in a row when you put numbers in order from smallest to largest. So 50% of the numbers (values in this case) will fall below the median, and 50% above the median. If your Grip test gives you an AMH value exactly equal to the median for your age, that means that 50% of women your age will have a lower AMH, and 50% a higher AMH.
You can also see the 2.5, 5, 95 and 97.5 percentiles on the chart. Let's take the 5th percentile for our explanation: if your AMH value is equal to the 5th percentile, that means 5% of women your age have a lower AMH, and 95% a higher AMH. This is the same for, for example, the 97.5th percentile (97.5% has a lower, and 2.5% has a higher AMH).
It becomes more difficult if your values fall between the percentiles in the graph. Because we don't have hard data points for, say, the 18th percentile, or the 78th percentile, we often can't say exactly where on the curve you fall. We can estimate where you are: with an AMH of 2.6 ng/ml at age 32 you are just below the median and well above the 5th percentile. Just over 50% of 32-year-old women will have a higher AMH, while perhaps ~30-40% of women will have a lower AMH.
Please note: the graph only contains the data for women without PCOS. In women with PCOS, it is difficult to tell about your ovarian reserve through AMH, because the small egg sacs on your ovary that are so characteristic of PCOS, produce AMH. We therefore do not know whether your AMH is high due to PCOS, or whether you have an above-average amount of eggs for your age.
A Grip test can tell you where your AMH levels are at. Wondering if our fertility test is right for you? Take our quiz to find out!
Anckaert E, Öktem M, Thies A, Cohen-Bacrie M, Daan NM, Schiettecatte J, Müller C, Topcu D, Gröning A, Ternaux F, Engel C. Multicenter analytical performance evaluation of a fully automated anti-Müllerian hormone assay and reference interval determination. Clinical biochemistry. 2016 Feb 1;49(3):260-7.