AMH levels (Anti-Müllerian Hormone levels)
How do the levels of AMH affect female fertility?
What are the normal levels of AMH? How do the levels of AMH affect female fertility? When is Anti-Müllerian Hormone considered to be high? What Anti-Müllerian Hormone value is low? What is the normal AMH value for your age?
If you are looking for an answer to all these questions you are in the right place, but before diving into the numbers, do you know what AMH is and what it is used for?
The Anti-Müllerian Hormone, also known as AMH, is a hormone that can be measured in the blood which helps evaluate a woman’s ovarian reserve.
Before starting any fertility treatment, your fertility gynecologist will measure your AMH value to have an idea of how many oocytes (or egg cells) are still present in your ovaries.
Your AMH value helps your fertility specialist to provide you with an estimate of the expected fertility treatment result and also guides the choice of the dosage of medication to be used for the stimulation of your ovaries.
What are the normal levels of AMH?
In general, when we consider assisted reproduction treatments, AMH levels ranging between 1 ng/mL and 4 ng/mL are predictive of a normal response to an ovarian stimulation.
What AMH value is low?
AMH levels below 1 ng/mL are considered “low” and are indicative of a poor ovarian reserve.
When is AMH considered to be high?
While an Anti-Müllerian Hormone level below 1 ng/mL predicts a poor response to ovarian stimulation treatments, AMH levels above 4 ng/mL are considered “high” and, in case of a fertility treatment, may predispose to the development of OHSS (or Ovarian HyperStimulation Syndrome).
Your ovarian reserve - the number of egg cells available to you in your ovaries for you to try to have children - decreases over the years.
The value of AMH also decreases with increasing age, in fact, your anti-Müllerian hormone value will decrease following the quantity and the speed with which you will lose your egg cells.
For this reason, measuring your AMH levels over time will allow your fertility doctor to understand how quickly and to what extent your ovarian reserve is diminishing.
Graph: AMH value curve according to age
The ovarian reserve defines the amount of egg cells still available in your ovaries.
The ovarian reserve decreases with advancing age and its decline becomes faster from about age 35.
Once menopause is reached, AMH levels are undetectable.
AMH levels rise steadily from birth to age 9, and then decrease slightly during puberty.
The levels of AMH peak around 25 years of age, after which they gradually decrease (due to the constant loss of the primordial ovarian follicular pool with age) until they are no longer detectable at menopause.
Important: the age-dependent rate of decline in AMH levels varies between women.
Measuring the value of AMH, is one of the fertility parameters that can help women make informed choices regarding their reproductive health, taking into consideration their current or future wish to have children and their “family-size goal”.
This said, the interpretation of your AMH value and it’s correlation to your ovarian reserve must be made by an expert in fertility and should extreme caution should be payed during adolescence and in young women under the age of 25 (since AMH reaches its peak level at age 25).
Understanding "average" AMH levels
If you have already measured your AMH value I am sure you want to know if your result is in line with your age or above/below the average value for women in your age group.
AMH is usually measured routinely only in women who experience issues conceiving, so the average levels are based on the AMH results obtained from a population including many women with fertility problems.
If you don’t have fertility issues, to better understand whether your AMH is in line with your age group, you should compare your result with the average levels obtained from a population of women without any known fertility problems.
A study performed by the Center for Fertility Research & Education looked at the AMH results of more than 2,600 tests (using Roche’s Elecsys test for measuring AMH) in women with no known fertility problems who wanted to assess their fertiity potential.
You can have a look at the median levels for every age according to this study here below.
Not all laboratories, however, use the same test to measure AMH.
This is another reason why, instead of just comparing your AMH result with the AMH levels you find online, you should always consult a fertility specialist to interpret your fertility exams!
What is the normal AMH value for your age?
Table: AMH levels based on age (according to study:)
anti-Müllerian hormone value at 26 years
anti-Müllerian hormone value at 27 years
anti-Müllerian hormone value at 28 years
AMH levels don't follow a bell curve distribution.
AMH doesn’t have a clear upper limit, but it has a very clear lower limit: zero.
This is the reason why, instead of comparing mean levels, we look at median levels.
let’s simplify what this all means: if your AMH value matches exactly the median value for your age, then 50% of women your age will have a lower AMH than you and the remaining 50% will have a higher AMH than your value.
Your fertility potential depends on the number of egg cells still available in your ovaries (which can be estimated by measuring your AMH), but also depends very much on the quality of the egg cells that are still available (and unfortunately AMH is unable to provide us with any data on egg quality).
Egg quality depends, above all things, on your age, but it’s also influenced by your lifestyle.
This is the reason why, it's important to consider both your AMH value and your age to be able to predict your response to a fertility treatment.
With increasing maternal age, oocyte quality decreases and consequently the chances of pregnancy are reduced, while the risk of having spontaneous abortions increases.
Graph: pregnancy probability and abortion risk according to maternal age
At this point you may have one of the following questions:
Your Anti-Müllerian hormone value can be influenced, usually resulting as lower, in case you are:
- using a hormonal contraceptive, especially in case of long-term use.
The levels of AMH in your blood in fact can decrease transiently, or in a non-permanent way, by about 20-30% during the use of hormonal contraceptives and up to two months after stopping the contraceptive. If you are taking hormonal contraceptives you should measure your AMH at least 2 months after stopping hormonal treatment or inform your fertility specialist so that this factor can be taken into consideration. - smoking.
Smoking also negatively impacts the quality of your egg cells so, in case you are smoking, stop as soon as possible to preserve your current and future fertility potential! Once the quality of our egg cells is “ruined” there is no way to “go back”!
In recent years, several studies have investigated whether AMH value measurement in obese women provides reliable results.
It is thought that, in case of obesity, AMH might result falsely lower, however, no consensus has yet been reached on this point.
Some scientific studies show reduced AMH levels in obese women, while others find no differences between AMH levels in obese women compared to normal weight women.
Is it true that Anti-Müllerian Hormone levels are higher in case of PCOS and why?
The value of the Anti-Müllerian Hormone appears to be significantly increased in women with Polycystic Ovary Syndrome (PCOS) due to an increased number of ovarian follicles that produce AMH.
The “threshold” levels of Anti-Müllerian Hormone that could be used as a guide in the diagnosis of PCOS are still under study and have yet to be precisely defined.
However, depending on the age group of the woman, the following “cut-offs” (or limit levels above which the woman is likely to have a polycystic ovary) have been proposed:
- 5.7 ng/ml in women aged 20 to 27 years,
- 4.55 ng/ml in women aged 27 to 35 years,
- 3.72 ng/ml in women aged 35 to 40 years.
Can Anti-Müllerian Hormone levels predict the age of onset of menopause?
The ability of AMH levels in predicting how long it will take to reach menopause is being investigated and the research to date is promising.
However, further scientific investigations are needed before AMH levels can be used for this purpose.
If you want to better understand what the Anti-Müllerian Hormone is, how it is measured, what effect it has on your fertility and how AMH levels are interpreted, read my article I’ve made for you!
