The ovarian reserve declines with age. All women need to know that they are born with the certain number of eggs, so usually they are reaching puberty with 300 -500 thousand eggs. This starts to decline and they are reaching the age of 37 years old having around 25 thousands oocytes. So, this means that the ovarian reserve declines with time. Now, the number, a specific number of AMH is not so predictive and not specific or sensitive to what is happening with every woman. So , basically there are certain numbers according to the age group that women belong to, usually, we have some cut-offs. So when we say that the AMH is more than 4 nanogram per ml, usually it is a very good ovarian reserve and it is high ovarian reserve, usually related to polycystic ovarian syndrome. When we have AMH which is very very low, like lower than 1 nanogram per ml, then of course we speak about low AMH but all the number we receive it is according to the women’s age group that she belongs to. There are only cut-offs for the lower part, there are no cut offs for the higher part of the AMH. AMH is hormone produced from very very small follicles, the follicles that we cannot visualise over scan examination, so it is first predictor how full is the deposit of the woman but this needs to be related with the age group that the women belongs to all the time and of course with the other ovarian biomarkers like the baseline FSH.
AMH level is one of the factors that is giving information about fertility. Normal range of AMH with scan of antral follicle count would inform us about ovarian reserve and age can indicate the quality of oocytes.
So the next question is, what is a normal AMH level as per a woman’s age? The Anti-Müllerian hormone, AMH, is a hormone produced by the granulated cells around the preantral follicles in the ovaries. When you go through menopause and have no preantral follicles left, the granulated cells stop producing AMH. So during a woman’s lifetime, from puberty through to menopause, she’ll produce AMH all the time at different levels, according to her age and how many antral follicles she has left. For this reason, we can create charts of what is the normal range for each age group.
So if you have an AMH that is well above the normal range for your age group, then maybe you have something called polycystic ovaries. If, however, you have an AMH that is much lower than the normal range for your age group, then maybe you have what we call a reduced ovarian reserve. And if you are in the normal range for your age, then you should be able to respond to ovarian stimulation in the same way as a woman of your own age, which means that if you’re 25, you’re probably going to respond very well. But if you’re 40, you may not respond so well. But that’s normal for 40-year-olds. So AMH gives you a guide as to your ovarian reserve, according to your age. It can vary a little according to your race. We did a study on Spanish women a few years ago and found that the average AMH level in Spanish women was found to be a bit higher than other European populations, but seemed to be lower than the Asian population.
