What Is the Function of Anti-Müllerian hormone (AMH)?

By BSc, MSc (embryologist), MD (gynecologist), (medical director at fertty international), BSc, MSc (embryologist) and (invitra staff).
Last Update: 05/27/2020

The Antimüllerian hormone (AMH) is a marker used to evaluate a woman's ovarian reserve and thus assess her fertility status at a specific moment.

High AMH values indicate that the ovarian reserve is optimal. However, as the age of the woman increases, these values decrease until ovarian depletion occurs.

The analysis of the AMH levels also provides information on the most appropriate assisted reproduction treatment to achieve a pregnancy: artificial insemination (AI), in vitro fertilization (IVF) or the need to resort to egg donation.

What is the anti-müllerian hormone?

HMA is a protein present in both men and women, but with different functions and locations. Its main role occurs during pregnancy, as it is responsible for the sexual differentiation of the fetus.

In the following section, we will explain the mechanism of action of AMH in relation to the sex of the fetus:

Male sex
AMH is produced by the testes around weeks 8 and 9 of fetal development in order to prevent the development of the Müllerian ducts, structures that lead to the uterus and fallopian tubes.
Female sex
the absence of HMA allows the female reproductive system to form in the fetus. However, AMH will begin to be expressed a few weeks later, when ovarian follicles are already present.

After birth, AMH levels remain high in males until adolescence, but in adulthood, they remain low.

In women, however, the anti-müllerian hormone begins to become important from puberty onwards, as it is produced by the ovarian follicles where the eggs develop.

AMH in women

Antimüllerian hormone is produced by the preantral and antral follicles of the ovaries throughout a woman's reproductive life, i.e. from puberty to menopause.

Specifically, it is the granulosa cells that surround the egg that is responsible for synthesizing it. Therefore, the measurement of the AMH in the blood indicates approximately the number of eggs a woman has, i.e. her ovarian reserve.

The antimullerian hormone is present in all follicles of both ovaries equally and is, therefore, a biological marker of fertility.

To evaluate female fertility, other analyses will also be taken into account: FSH and LH hormone values, antral follicle count by transvaginal ultrasound, etc.

Find more information about this topic here: What Can Ovarian Reserve & AMH Tests Tell Us?

When to perform an analysis?

As we have said, the antimüllerian hormone is synthesized by the antral and preantral follicles of the ovary. These are growing basal follicles, which have not yet been selected to mature into dominant follicles.

The importance of this is that AMH values do not vary with the menstrual cycle. The blood test can, therefore, be done on any day of the cycle without influencing the results. It is also not necessary to fast.

However, it should be borne in mind that other female hormones are normally also looked at to assess fertility, such as FSH and estradiol, especially before undergoing assisted reproduction treatment.

For all this, it is more practical to perform a single hormonal blood test in the basal state, which is the first days of the cycle: 3-5 days after the start of menstruation.

AMH values

The AMH reference values are well defined and it is possible to know more or less exactly what the woman's current fertility status is at the time of the analysis.

However, since there are several methods for detecting AMH, it is difficult to compare the levels obtained between different techniques. It is best to interpret each patient's results according to the cut-off values of each test.

We will now establish the reference ranges of the technique most commonly used in laboratories, although there may be slight differences.

Very high AMH
niveles mayores de 6 ng/ml. They indicate that there may be a risk of ovarian hyperstimulation syndrome when administering hormonal medication in an IVF.
High AMH
between 3 and 6 ng/ml. The ovarian reserve is good.
Normal AMH
between 1 and 2,9 ng/ml. The ovarian reserve is good.
Normal low AMH
between 0,7 and 0,9 ng/ml. The ovarian reserve has begun to decrease, although it is still within normal range
Low AMH
between 0,3 and 0,6 ng/ml. Suggest a low ovarian reserve and, as a consequence, the patient is likely to have a low response to hormone stimulation.
Very low AMH
levels lower than 0.3 ng/ml The ovarian reserve is almost exhausted and the woman is close to menopause. Egg donation is most likely needed to have children.

In other hormone analyses, it is possible to find the AMH values in the units of pmol/l.

Finally, it is worth mentioning that women with polycystic ovaries have the highest antimullerian hormone and that it decreases more slowly with increasing age. This implies that these women have more delayed ovarian aging.

Anti-Mullerian Hormone by Age

As a woman's age increases, her ovarian reserve decreases and, consequently, so does her anti-mullerian hormone.

The most drastic drop takes place from the age of 36, but there are some women who can count on a low reserve even earlier. This would be the case with early menopause.

Knowing the state of fertility and the ovarian reserve can help women to better plan their motherhood and make decisions like the following:

  • Preservation of fertility if she wants to become a mother in the future, i.e. freezing the eggs for later use.
  • Bringing motherhood forward to the near future in the case of a normal-low reserve.
  • Undergoing an assisted reproduction treatment if AMH has resulted in a low value.

Since the analysis of the anti-Müllerian hormone can be a bit expensive, it is also possible to assess the ovarian reserve with an ultrasound and the FSH level.

The value of AMH is directly proportional to the number of antral follicles in the ovary and, therefore, to the ovarian reserve.

In contrast, FSH values vary in reverse: the lower the ovarian reserve, the higher the FSH hormone.

AMH and assisted reproduction

Another of the advantages of this hormonal determination is that it is very useful for assisted reproduction professionals, as they can decide which treatment is most suitable for each patient, as well as the pattern of hormonal medication required.

It has been shown that there is a correlation between the values of HMA and the degree of ovarian response to ovarian stimulation. Thus, patients with high AMH may be at risk of hyperstimulation, while patients with low AMH are more likely to have a low response.

The latter, therefore, will need higher doses of gonadotropins to achieve multiple follicular development.

AMH can be useful to better predict the success of assisted reproduction treatments and to be able to make a more accurate indication of the appropriate technique for each patient.

In addition to all this, the anti-Mullerian hormone also allows a better study of fertility physiology, since its levels have also been related to the quality of the eggs. It is said that only healthy follicles, which will give rise to a high-quality oocyte, are capable of producing AMH.

AMH in men

Although this test is not as widely used in men, AMH is a good marker of testicular function.

In particular, AMH is synthesized in Sertoli cells, where sperm formation (spermatogenesis) also occurs.

Analysis of AMH in men can be performed at diagnosis of azoospermia (absence of sperm in the ejaculate). In this case, AMH helps to determine whether or not there are sperm in the testicle.

These could be removed by biopsy and used in an intracytoplasmic sperm injection (ICSI) to fertilize the woman's eggs.

However, AMH in men is a predictor that is not as effective as in women and, ultimately, better results are obtained through FSH analysis.

AMH test costs

The determination of AMH in blood is a test that can be performed within the female fertility testing or separately. Prices can vary greatly depending on the clinic and laboratory where it is done.

In general, female fertility studies cost $150-500 and include pelvic ultrasound. Apart from this, fertility-related blood tests are charged $200-400 and the most expensive ones include AMH testing.

If only the AMH test is performed, the price is about 100$.

In assisted reproduction, like any medical treatment, it is necessary for you to trust the professionalism of the doctors and the clinic you choose.

This Tool generates you a personalized report with all information necessary about the treatment you will need. Besides, there is a list of clinics in your area which we have chosen based on our selection criteria with their budget plan included. Last but not least, you will find a series of useful tips for your first clinic visit.

FAQs from users

What information does the Anti-Müllerian hormone analysis provide?

By Dr. María Arqué (medical director at fertty international).

Anti-Müllerian hormone is produced by the preantral and antral follicles of the ovaries throughout a woman's reproductive life.

Specifically, responsible for synthesizing it are the granulosa cells that surround the egg. The measurement of AMH in blood indicates approximately the quantity or number of eggs a woman has, i.e. her ovarian reserve. To complete the information on the ovarian reserve it is necessary to perform a transvaginal ultrasound with an antral follicle count.

It is important to remember that both the AMH and the antral follicle count are quantitative markers and do not provide us with information about egg quality. The parameter that best correlates with the quality of the oocytes is the woman's age.

At what age should AMH be examined?

By Dr. Elena Santiago Romero MD (gynecologist).

Anti-Müllerian hormone is produced by the ovary, and its blood levels are an indicator of a woman's ovarian reserve.

To ensure everything works as expected, we recommend that the first measurement is done from age 20 and not later than age 30. By doing this, if a woman has a diminished ovarian reserve at a young age, she would have time to decide whether she wants to have a baby now or cryopreserve some eggs to become a mother in the future.

Can I get pregnant naturally with a low AMH level?

By Zaira Salvador BSc, MSc (embryologist).

Low AMH values are an indication of a low ovarian reserve. However, it is only reported that the chances of pregnancy are reduced, not impossible. It depends on the exact value obtained and other factors such as the quality of the partner's semen, the permeability of the fallopian tubes, endometrial receptivity, etc.

Why can't I get pregnant even though my AMH level is high?

By Zaira Salvador BSc, MSc (embryologist).

A high AMH level indicates that the egg reserve is good. However, there may be other changes that affect your fertility. In these cases, it is best to have a full fertility check-up to analyze which factors can prevent you from getting pregnant.

Can you improve low AMH levels?

By Zaira Salvador BSc, MSc (embryologist).

Basically not. AMH is an indirect measure of the number of eggs in a woman's ovarian reserve and there is no treatment to increase egg production. However, some women experience a slight improvement in their AMH levels by living a healthier lifestyle. Quitting smoking, eating a healthy diet or losing weight are habits that can improve the quality of the eggs, which could be reflected in the AMH level.

Lectura recomendada

To learn more about the women's ovarian reserve, we recommend that you read on here: What is the Ovarian Reserve and How Does It Affect Fertility?

To read more about the AMH test and other important examinations, you can read the following article: Can a Women's Egg Count be Measured with a Blood Test?

Our editors have made great efforts to create this content for you. By sharing this post, you are helping us to keep ourselves motivated to work even harder.

References

Authors and contributors

 Cristina Mestre Ferrer
Cristina Mestre Ferrer
BSc, MSc
Embryologist
Bachelor's Degree in Biological Sciences, Genetics & Human Reproduction from the University of Valencia (UV). Master's Degree in Biotechnology of Human Assisted Reproduction from the UV and the Valencian Infertility Institute (IVI). Embryologist at IVI Barcelona. More information about Cristina Mestre Ferrer
Dr. Elena Santiago Romero
Dr. Elena Santiago Romero
MD
Gynecologist
Bachelor's Degree in Medicine and Surgery from the Autonomous University of Madrid. Master's Degree in Human Reproduction from the King Juan Carlos University and the Valencian Infertility Institute (IVI). Several years of experience as a gynecologist specializing in Reproductive Medicine. More information about Dr. Elena Santiago Romero
License: 282864218
Dr. María Arqué
Dr. María Arqué
Medical Director at Fertty International
Doctorate in Reproductive Medicine at the Autonomous University of Barcelona, specializing in Obstetrics and Gynecology. Dr. María Arqué has many years of experience as a Reproductive Medicine and Gynecologist Consultant and currently works as Medical Director at Fertty International. More information about Dr. María Arqué
Licence number: 080845753
 Zaira Salvador
Zaira Salvador
BSc, MSc
Embryologist
Bachelor's Degree in Biotechnology from the Technical University of Valencia (UPV). Biotechnology Degree from the National University of Ireland en Galway (NUIG) and embryologist specializing in Assisted Reproduction, with a Master's Degree in Biotechnology of Human Reproduction from the University of Valencia (UV) and the Valencian Infertility Institute (IVI) More information about Zaira Salvador
License: 3185-CV
Adapted into english by:
 Romina Packan
Romina Packan
inviTRA Staff
Editor and translator for the English and German edition of inviTRA. More information about Romina Packan

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