We have a large number of hormones in our body that help cells perform their functions. We may be familiar with some of them, such as dopamine or serotonin, the famous happiness hormone. But there are many more in our body. One of them is anti-Müllerian hormone (AMH). Although the concept may seem a bit complicated, it is due to the name of the paramesonephric ducts of the embryo, also known as Müllerian ducts. Hence, the hormone that causes these ducts not to develop in babies with male reproductive organs is called ‘anti-Müllerian’. We know it can be a bit complicated to understand at first, so we are going to unravel all the concepts little by little, from the complete definition of this hormone, how it affects development and what its analysis would be useful for.
What is antimüllerian hormone?
Antimüllerian hormone is a chemical substance produced in the reproductive tissues (testes and ovaries). Its amount varies according to age and sex. This hormone is very important during the early stages of development of a baby, especially a male baby. The testicles will be in charge of generating the anti-Müllerian hormone, which will cause the development of the female reproductive organs to stop, promoting instead the development of other male reproductive organs. It is during the first weeks of pregnancy that the fetus has the potential to form either male or female reproductive organs. The testes will produce both AMH and androgens to stop the development of female reproductive structures (Müllerian ducts) and, at the same time, promote the creation of male reproductive organs.
If during this process there is not enough AMH, ambiguous sex organs (intersex persons) may develop. Therefore, this hormone basically ‘instructs’ the cells to generate male reproductive organs in XY-chromosome babies. Therefore, the concentration of AMH in infants with male reproductive organs is high until puberty. After that stage it begins to decrease.
In infants with an XX chromosome the opposite occurs, as the hormone will promote the creation of female reproductive organs. The concentration of AMH is low in these cases until puberty. From this stage on, the ovaries begin to produce anti-Müllerian hormone, so its concentration increases. From this point on, its quantity begins to decrease, until, after menopause, the hormone is barely detectable.
This hormone remains very important throughout the baby’s development, especially during the childbearing years. When a baby with an XX chromosome is born, it has about 1 million eggs. This number obviously decreases naturally during infancy, until there are about 500,000 eggs left. Of these, only a small number will enter the follicular maturation phase (1 is released each menstrual cycle). Antimüllerian hormone maintains the balance of the cyclic variations of the hormones lutropin and follitropin during maturation and egg release. The amount of AMH present is therefore a reflection of the development of the ovarian follicle.
Usefulness of an AMH assay
For a long time it was thought that an anti-Müllerian hormone was only involved in fetal sexual development. However, in recent decades its usefulness as a marker of ovarian function has been discovered.
In fact, there are already many studies showing that AMH concentration can be useful in predicting ovarian reserve and the chances that a person will or will not be able to become pregnant. As anti-Müllerian hormone decreases during the patient’s fertile life and especially as menopause approaches, it may be detectable after menopause. This is why AMH analysis is so useful in assessing a patient’s fertile status, as well as helping to determine the onset of menopause. With this data, a fertility diagnosis can be created to see when, if it is the patient’s desire, would be the ideal time for pregnancy.
The relationship between anti-Müllerian hormone and polycystic ovary syndrome (PCOS) has also been studied. The excess number of follicles seen in this disease causes an abnormal increase in AMH. This hormone can also be elevated in certain ovarian tumors (benign or malignant). If this tumor produces AMH, it can be used as a tumor marker to analyze the effectiveness of the treatment given to the patient, as well as to help detect recurrences.
How is the antimüllerian hormone test used?
Antimüllerian hormone testing is not often requested. However, there are certain circumstances in which the physician may require it. Let’s divide the categories into adults and infants.
AMH in adults. When there are cases of infertility, AMH helps predict ovarian reserve. It is usually requested together with an analysis of FSH or estradiol hormones. It can also be used prior to any assisted reproductive technique, such as in vitro fertilization. The AMH concentration is associated with the success rate of the treatment. If the amount of this hormone is low, it means that the ovarian response is poor; most likely very few eggs will be retrieved after the ovarian season. If the analysis is ordered for this purpose, it is usually accompanied by a transvaginal ultrasound to count the number of follicles. As discussed above, this test may also be ordered when there is suspicion of polycystic ovary syndrome or ovarian cancer (AMH would be used as a marker).
AMH in infants. Anti-Müllerian hormone may be used in infants with ambiguous genitalia in order to assign a sex. It will usually be accompanied by a chromosomal study, a hormonal study or imaging tests.
When should I order the test?
The test may be ordered to test ovarian function and fertility. Also to observe if the menopausal phase is approaching or if symptoms of possible polycystic ovary syndrome are present. Some of them are:
- Uterine bleeding outside the menstrual period or of abnormal characteristics.
- Acne.
- Amenorrhea.
- Small breast size.
- Enlarged ovaries.
- Hirsutism (hair on the face, sideburns, chin, upper lip, midline of the abdomen, chest, nipple areola, lower back, buttocks and inner thigh).
- Obesity or weight gain.
- Small warts in armpits or neck.
- Thinning hair.
- Male pattern baldness.
AMH may also be requested in cases of ambiguous genitalia in infants or when ovarian cancer is present.
The results of the test can be in 1 or several days. It is necessary to mention that the analysis of this hormone requires specific instruments and, therefore, the sample must be sent to a reference laboratory. You can consult with our team any type of test before even requesting it.
How to interpret the results?
In the case of an adult patient, a low AMH concentration during menstruation may indicate that there are few eggs and, moreover, of poor quality. This would result in low fertility, which at the same time would result in minimal or even no response to in vitro fertilization procedures. It may also mean that the ovaries are not functioning normally (early ovarian failure). If the AMH concentration is high, it may mean the opposite: that the response to ovarian stimulation is very high or even excessive. In this case it would be necessary to customize the dose of fertility treatment.
In case AMH concentrations are progressively decreasing at a particular time it could mean the onset of menopause. In polycystic ovary syndrome, on the other hand, elevated AMH concentrations are found, although they are not diagnostic of the disease.
If anti-Müllerian hormone is used to monitor ovarian cancer, its decrease would indicate a positive response to treatment, while its increase would indicate a recurrence of the disease.
In infants, when there are ambiguous genitalia and karyotype with XY chromosomes together with an absence of AMH or a low concentration, it may indicate alterations in the gene for this hormone (chromosome 19). This is responsible for regulating the production of anti-Müllerian hormone and may be altered in testicular dysfunction. If this is the case, abnormal reproductive structures can form. If a baby has undescended testes, an abnormal concentration of AMH and androgens indicates that these are present and functioning, although they are not found in the scrotum.
In a fetus with an XX chromosome but a male phenotype, a high concentration of AMH tells us that the cause could be the presence of testicular tissue. A low concentration, on the other hand, indicates a probable adrenal origin.
Conclusions about antimüllerian hormone
There is some discussion among the medical community when it comes to ordering antimüllerian hormone tests. Some believe and advocate more routine use, as it can help predict the end of fertility, help as a tumor marker in case of ovarian cancer or diagnose a possible case of polycystic ovary syndrome. The ‘problem’ is that AMH is not considered today to be diagnostic on its own, but is more of a sort of tool to aid in diagnosis.
Therefore, from Ambar Lab we want to make this hormone test available to anyone. Our team is constantly researching to make available to all customers the latest advances in medicine and laboratory tests. We hope that this information has served to raise awareness and to learn the existence and function of such a fundamental hormone for our body.
