AMH can offer a clue to assessing your reproductive aging timeline.
AMH stands for Anti-Müllerian hormone. Both males and females make AMH. In females, it’s made in the ovaries.
Specifically, AMH is made by the cells of follicles (eggs) as they develop. While a person is cycling, follicles are constantly developing in groups and producing AMH even though only one egg becomes the dominant follicle each cycle and gets released at ovulation. A refresher on the basics of the menstrual cycle can be found here.
The amount of AMH in your blood is a proxy for how many follicles you have left and the quality of those follicles. As such it’s a metric used in fertility and more recently to predict the time to menopause, the final menstrual period.
For most people, AMH peaks in the mid-20s (with fertility) and then begins to decline as the number of eggs (ovarian reserve) declines as such it’s a measure of reproductive aging. You can see how many eggs a female has at birth and how the number changes across our lifespan here.
For whom and how might AMH be helpful during perimenopause?
Three scenarios:
Scenario #1: I don’t get a period because of a surgery, a procedure, or my birth control method so I can’t use changes in my periods to gauge that I might be in perimenopause. So, how can I tell if hormonal fluctuations are the cause of my symptoms?
For those who have had a hysterectomy, an endometrial ablation, or are using an IUD that prevents a period, you can’t tell whether your ovaries are still active by periods coming closer together or farther apart or more or fewer days of bleeding or more or less flow per day. And you also won’t know when your period ultimately stops. So, if you are having hot flashes or night sweats and other symptoms possibly related to reproductive aging (i.e., wonky hormone levels), an AMH test might offer useful information.
What you’d learn:
If your AMH levels are very low or undetectable, it is safe to assume that symptoms are due to perimenopause and treatment might provide relief. This is helpful for those of us that want to be sure about a link between symptoms and hormonal changes before managing symptoms with hormones. A low AMH can confirm that the symptoms are likely related to reproductive aging.
#2: My flow is so heavy that it gets in the way of things I want to do. If I knew I was close to my final menstrual period, I might wait it out. Otherwise, I’d like to treat it surgically.
Those who have very heavy menstrual bleeding, fibroids, or other issues that cause them to contemplate a hysterectomy (or ablation) but who are perimenopausal might want to consider testing their AMH.
What you’d learn:
If you are 48 years old or older, and your AMH level is undetectable, then you are 90+ percent likely to be menopausal within the next 12-24 months. The information that your final period is likely to be soon, might cause you to try to manage the heavy bleeding with medication rather than surgery. Conversely, if your AMH is high and it looks like menopause is at least a few more years off, you may opt for the surgery to avoid the continued bother of bleeding or side effects of hormones.
#3: I don’t get a period because of a condition, a medication I take or I’m an extreme athlete. So how can I tell if my new symptoms are related to changing hormonal patterns? (Similar to #1 above).
Some health conditions (e.g. a prolactin disorder), medications, or being an endurance athlete can cause periods to stop.
What you’d learn:
As in example #1 above, if your AMH level is low, you can tell if your symptoms are likely caused by hormonal changes and that may help you feel more confident about one treatment versus another.
If you are now curious about your AMH level
If one of the above scenarios applies to you, discuss checking your AMH level with your healthcare provider. Historically, AMH has mostly been used in fertility and so many healthcare providers don’t know about the new data related to the perimenopausal relevance of AMH levels. Also, not all AMH assays are the same. The studies about time to menopause used a very sensitive assay that is not yet widely available.
For those that want to read up further, here is an open access paper and a really deep dive on AMH.