Today, we are going to talk about a hot button issue in fertility: AMH, or anti-mullerian hormone.
Supposedly “AMH decreases as the age of the women increases naturally. Women have commonly low AMH results over the age of 40.” Or so they say…
AMH is being used in fertility circles to screen women for low ovarian reserve. However, I find that it is being used improperly (i.e., applied to natural fertility), without appropriate caveats (i.e., what factors besides age can affect it) and often as a scare-tactic to pressure women into fertility procedures.
This is a nuanced topic, so it’s probably going to take a few posts to unpack.
Let’s start with what AMH is:
AMH is a hormone produced by the developing follicles in a female’s ovaries.
Essentially, a high AMH level suggests a higher number of eggs or ovarian reserve. A low AMH level may indicate that you have a lower ovarian reserve.
These are the facts that we currently understand. However, what people are making these facts mean is that high AMH = good and low AMH = bad. Unfortunately, that’s oversimplified and not really accurate.
Here is what AMH is best used for: predicting your response to fertility treatments such as egg freezing and IVF.
Here is what AMH may be useful for, when used in context with other markers: an indicator of decreased fertility or early menopause (if lower than expected) or an indicator of PCOS (if higher than expected).
Here is what AMH is not relevant for: natural fertility outcomes.
So, let’s take a look at my personal situation as an example.
My AMH is higher at age 40 than it was at age 33.
Here are my numbers:
Age 31 (9/19/14)
Age 33 (7/19/17)
Age 40 (2/22/24)
In summary, my AMH was in a normal range at 31, went down meaningfully at 33 (still “normal” but below the median for my age) and then rebounded by age 40. I wish I had tested my AMH again in my late 30’s for comparison purposes, but unfortunately I didn’t.
Does this mean that I’m more fertile at 40 than 33? Maybe, but not necessarily.
We would need to take into account other factors, such as my hormone levels (e.g., FSH, LH, estradiol). I would need to look at other indicators that could affect my fertility, such as inflammation, metabolic function, immune system regulation and nutrient deficiencies. Luckily, I have all of this information and can compare and contrast my trends over time.
Interestingly though, based on my AMH alone, this technically suggests that I’m a “better candidate” for egg freezing at age 40 than at age 33. I’ve also looked at my antral follicle count (another indicator of ovarian reserve) and that correlates with my AMH results.
Given the line of work that I do, I am probably a rare breed who has been tracking AMH for a decade. However, lest you think this is only true for me - I literally just saw a client who increased her AMH by over 30% in ~6 months.
AMH is not what we have been led to believe. If AMH was truly a proxy for egg quantity, then it should only move in one direction - down. So, why do we see it move upwards?
There are several factors that can artificially depress AMH that we know of, some of which probably played a role in my own story. There are likely many others that we don’t yet know about.
I will dive into some of these factors next week. Until then, know this: According to a 2017 JAMA study, “Among women attempting to conceive naturally, diminished ovarian reserve was not associated with infertility; women should be cautioned against using AMH levels to assess their current fertility.”
Given what I shared above, I would agree with this assessment. AMH is one data point among many that can give us information about our potential fertility, but it must be taken into context and it must be applied to the contexts where it is relevant and not used in contexts where it has no predictive value.
It’s always a bit vulnerable to share your own story - and certainly your health data - so I want you to know that I’m exposing this in the hopes of being of service to all of you. I welcome your reactions and feedback.