What is there to know about AMH?
Women are born with an ovarian reserve that decreases with age until the woman reaches menopause when the reserve is almost completely depleted. Literally, all the eggs a woman will ever have exist in her ovaries since she is a fetus in her mother’s womb.
At birth, a baby girl has around 1 to 2 million eggs in her ovaries.
When the girl reaches puberty, her ovarian reserve will have decreased to 300.000-400.000 eggs.
Around age 25, when women are in their peak reproductive age, only around 25.000 eggs remain.
By the time a woman hits menopause, her ovaries will hold less than 1000 eggs.
These are averages, and it goes without saying that numbers vary from one individual to another, but one thing is clear: for most women, the biggest drop in fertility (based on both quantity and quality of eggs occurs around the age of 35).
All these eggs, forming the ovarian reserve, produce a hormone called Anti-Müllerian Hormone (in short, AMH), which circulates in your blood.
Testing the levels of this hormone can give you a pretty good idea of your ovarian reserve at the moment of testing. We say that AMH is one of the best markers of ovarian reserve, and it is used for IVF clinics as an indicator of response to ovarian stimulation treatments. Basically, the more eggs a woman will have, the better the chances of getting a good response to stimulation meds and of retrieving more oocytes in case an IVF treatment is needed.
When AMH levels are out of range
We expect a lower AMH as a woman gets older, but there are some situations where women have lower than normal AMH levels, and a Diminished Ovarian Reserve (DOR) at a younger age, and here are some reasons for it:
- Premature Ovarian Failure (DOR occurs before the age of 35)
- Previous chemotherapy (cancer patients are sometimes offered the option to freeze their eggs before starting chemo)
- Surgery on one or both ovaries (for Endometriosis, for example)
Sometimes, women have AMH levels above normal. Since AMH reflects a woman’s ovarian reserve, that means a woman has more eggs than the average number expected for her age.
High AMH levels are usually an indication of PCOS (Polycystic Ovarian Syndrome), a very common endocrinological disorder among women of childbearing age.
PCOS is very common in the UAE, where it is estimated that up to 25% of women are affected.
What is a normal AMH level, and how do levels vary by age?
You need to keep in mind that the “normal level” for a 25-year-old is different than the “normal level” from a 40-year-old. And also, that levels are expected to diminish as a woman gets older.
Another important aspect is that different labs use different equipment and calibrations, so AMH levels may vary from one lab to another. It is highly recommended that you stick to one lab when you want to have your AMH tested and retested.
What are the strengths and limitations of AMH?
We have seen what AMH is, how it evolves during a woman’s life, what happens when levels are out of range.
But is AMH the be-all and end-all of fertility? Is it the decisive factor?
The short answer would be “no”.
Having your AMH levels measured is extremely important if you are considering freezing your eggs, if you are about to embark on an IVF journey or you’ve been trying to conceive for a while without success. You also need to test your AMH if you have PCOS symptoms and doctors are trying to confirm a diagnosis.
AMH is a great marker of fertility and a first step in evaluating your ovarian reserve.
Usually, and especially if the results are out of range or inconclusive, your doctor will order other tests:
- FSH (it is expected to be high in Diminished Ovarian Reserve)
- Ultrasound (to correlate AMH levels with the number of follicles found on your ovaries at the beginning of a cycle)
The truth is that AMH information plays an essential role in assisted reproduction and may help your decision if you should maybe preserve your fertility if you are not yet ready to start a family.
What AMH can’t do is predict the success of natural conception. In other words, if you are otherwise healthy and do not have any issues preventing conception, low AMH alone doesn’t mean you can’t get pregnant. This explains why there are women who get pregnant naturally in their early 40s when ovarian reserve is diminished and AMH levels are most likely on the lower side.
AMH may also be an indicator of egg quality. Additionally, we can say that women who have fewer eggs due to age also have poorer egg quality because egg quality is ultimately influenced by age.
At ART fertility centers, we offer AMH testing, alone or coupled with other tests, to assess your ovarian reserve and reproductive health.
Book your appointment now and let our specialists guide you in your journey.
