(AMH) Anti Müllerian hormone test – Can it predict the future?
If you read Twitter and look at some clinics marketing material you could be forgiven for thinking that the anti Müllerian hormone is the new Nostradamus of the IVF world. But are the claims of AMH’s future prediction capabilities warranted…
Let’s find out.
What is AMH Hormone
Anti Müllerian hormone is a protein hormone which is vital in the development of the reproductive organs in a male fetus. It is produced before birth by the testes and the ovaries. It continues to be produced by the ovaries in women and is thought to be able to be used as a predictor of ovarian reserve.
The image to the right gives you a good overview of what AMH hormone is.
What are the normal ranges for Anti Müllerian hormone test?
Before we investigate the uses of AMH and whether it can be used to predict the future we need to understand the levels.
The Anti Müllerian hormone test is performed in a lab from a blood test. There are a couple of really important things to note about the AMH lab tests they are
- The results can be presented in 2 common ways ng/ml or pmol/L so it’s vital that you check it against the right units.
- There are many types of tests known as assays to measure AMH; although the two most common are the Beckman Access assay and the Roche Elecsys AMH assays. Which can give varying results sometimes in excess of 10% if you are interested in reading more a 2018 cohort study examined the variability of these 2 tests and one more, which you can find here
The graph below shows the change in AMH levels in pmol/L over age.
Some specific important points to note are
- The normal range when you are younger is large
- The breadth of the graph diminishes as you get older which reflects the diminishing ovarian reserve
- The steep steps are at specific junctures where on average there is a reduction in fertility
This means that when you have the AMH test your clinician must interpret the results using their knowledge of the specific test that was used, your specific age and then this can determine your ovarian reserve….
Or does it?
Predicting your fertility based on AMH
From the information that we have given you thus far, you could come to the conclusion that it is a test which allows us to gaze into our fertility future so to speak.
It should be able to tell them how many eggs they have left, how long they can expect to be able to conceive naturally, when to expect the menopause. All great stuff, but does the research actually mean that these things are true. Let’s take a look at each one in turn where it is a useful predictor and where the future is a little more hazy.
Where the Anti Müllerian hormone test can be predictive of the future
The AMH test has a singular applicable use in predicting future outcomes.
Can you guess what it is?
Ok we’ll tell you it’s in how your ovaries will respond to stimulation medications through IVF treatment.
The data show’s that around 1 in 3 women respond poorly to ovarian stimulation and unfortunately that means that they often get less eggs and as a result it results in less live births than equivalent responders in the same age bracket.
At the complete other end of the spectrum, there are women who respond too well! These women often develop lots of huge follicles which resemble large bunches of grapes. Sounds great you might think, that means more eggs and whilst this ‘could’ (it’s not always) have more eggs, it’s very common for these eggs to be of very poor quality and you are at much greater risk of developing OHSS which you can read about in our guide. This group of women also have a lower live birth rate than those in the same age group.
I always think of the stimulation phase a little like the three bears. The calm and gentle baby bear is for underestimated ovaries, the big aggressive daddy is huge ovaries and the mummy bear has her ovaries just right.
These graphs from a 2014 article by Marca and Sunkara demonstrate the point well
You want people to fall between the 4-15 eggs otherwise the risks of a cancelled cycle and OHSS become too high.
So how do we make sure that we choose the right protocol (treatment option)? Well AMH is great predictor of ovarian stimulation, a number of studies have specifically demonstrated a very strong correlation between ovarian response and AMH levels.
Your AMH results can then be used to advise you on the appropriate stimulations protocol. We won’t go into specifics, but if you are within the normal range and expected to have a normal ovarian response you’d have the standard dose of stimulation medications and these would be adjusted based upon whether they expect you to respond well or poorly.
Where the AMH test does not allow you to see into the future.
Well sadly pretty much every other one of these predictions has either been disproved or still doesn’t have enough evidence to support. We will take a quick look at each of these in turn
Short term chance of natural conception
I have seen some clinics or labs, offer AMH level tests to check your current fertility and offering It as a guide as to your chance of natural conception! Do NOT believe this. A recent study looked at 1,202 women with the full spectrum of AMH levels from high through normal to very low.
They found that natural pregnancy rates where virtually identical – you can read the study here.
Long term fertility
Again, many commercial labs and clinics offer the AMH test to measure ovarian reserve as a hook they talk about it being a predictor of your long term fertility.
At this present time there are no studies or trials which show AMH can be used to predict future fertility.
What we know and you have learnt above is that your AMH does naturally decrease with time. But what you have also learnt is that the normal range is different for every woman. The difficulty is that the AMH hormone test is a snapshot of that exact moment the blood was taken and each women will have their own fertility decline at their own rate.
If like me you then think, “Ok, what if I get it tested regularly say, every 6 months, then surely that can predict my long-term fertility”
There are two problems, yes, you will see a decline over time if you test regularly but as AMH can’t predict pregnancy in the short term, see above or in IVF see next section then it seems improbable that it can predict pregnancy in the future.
Food for thought.
As a predictor of pregnancy in IVF
As we showed earlier it is amazing for showing how you are likely to respond to stimulation, which means if this is used to get you on the right protocol then you have the greatest chance of making it safely to implantation. Thus, giving you the best chance, you can, of a successful cycle.
However, a really important point to note is that it is not good at predicating who will get pregnant. Sadly, that is still unknown and would be the holy grail for fertility treatment. This is because it doesn’t consider, egg quality, age, the reason for infertility, other physical reasons and other treatment options.
PCOS: Polycystic Ovarian Syndrome, AMH and ovarian reserve
You may have noticed on the graph of change in AMH based on age, there was this top part of the graph where it specifically states possibly polycystic. Well this section is why.
PCOS is a condition which according to the world health organisation and NICE can only be diagnosed if a minimum of 2 of the following criteria are met
- Very irregular or lack of periods
- Blood tests showing increases in male hormones including testosterone. (sometimes specific signs of excess male hormones are enough in a normal blood test)
- Ultrasound scan showing polycystic ovaries.
This guide isn’t about the condition specifically, if you want to learn more then check out the charity Verity they have some very useful information about PCOS.
The reason that I mentioned the diagnostic criteria is due to the face that AMH doesn’t feature on that list. Although it is clear that women living with PCO often have high levels of AMH hormone. The reason for this is currently not known; it could be due to having more follicles or due to overproduction caused by the condition but until research is done this will not be clear.
One thing that is really important to note is that because a women with PCOS has a high (AMH) Anti Müllerian hormone test reading this does NOT mean that they have a better ovarian reserve and in fact egg quality is often diminished in those who suffer with PCOS when compared to normal ovaries.
Whilst AMH is a vital hormone, some of the hype, excitement and marketing around AMH being a miracle test is misplaced. It can certainly help in the IVF process ensure that people are less likely to have a cancelled cycle, have the lowest possible chance of getting OHSS and helping determine the best treatment protocols.
Who knows in the future AMH may be able to be used to look more carefully at a woman’s fertility long and short term? But at the moment the evidence is either running contrary to this or just not been explored; as such its Nostradamus status is here by revoked!