AMH Test: All About Anti-Mullerian Hormone Levels and Normal RangeFertility Treatment
The AMH test, or the ovarian reserve test, is one of the most important female fertility tests. This test measures AMH or anti-mullerian hormone levels secreted by Antral follicles. Interpreting measures of ovarian reserve or oocyte quantity plays a key role in determining the appropriate dosage of fertility medications, especially the ones used in IVF treatment.
High AMH levels (more than 1 ng/mL) usually mean that a woman has a normal AMH range, while low AMH levels (less than 1 ng/mL) may indicate diminished ovarian reserve (DOR).
What is AMH?
Anti-müllerian hormone, also known as Mullerian-inhibiting substance (MIS), is a glycoprotein secreted by granulosa cells of primary ovarian follicles during puberty and fertility. Since AMH is produced only by small Antral follicles with a diameter of less than 6 mm, its count in the blood can measure the growing follicles and the total ovarian reserve.
There is no anti-müllerian hormone in follicles larger than 8 mm, so the Anti-mullerian level is almost constant in the body. Aging causes diminished ovarian reserve (DOR) and will decrease the level of AMH in the body. On the other hand, when there are many small follicles in the ovary - like in PCOS -the level of AMH increases. Therefore, an AMH test is recommended. An increase in AMH levels will be very helpful in diagnosing PCOS.
How is Anti-mullerian (AMH) Secreted in Men and Women?
Testicles produce AMH in men and ovaries in women. In young boys, testicles secrete AMH hormone from early birth to prevent the formation of the female reproductive system and help the growth of male organs. The concentration of AMH in boys continues to increase until puberty, which then begins to decrease.
In girls, the situation is the opposite. As AMH secretion promotes the creation of female reproductive organs, the AMH level is low until puberty and then increases by the ovaries. However, AMH starts to decline at menopause and drops to an undetectable level.
Applications of Anti-Müllerian Hormone Test
Anti-Müllerian hormone test is used in the below cases:
- Evaluating both the ovarian health and ovarian reserve as well as the condition of the follicles in the process of fertility treatment;
- Measuring the polycystic ovary syndrome (PCOS);
- Evaluating ovarian cancer as well as the effectiveness of its treatments;
- Evaluating fetal conditions and diagnosing its gender;
- Predicting the onset of menopause;
- Finding the causes of premature menopause;
- Determining the causes of primary amenorrhea (not having a period by age 15) or the absence of menstruation at an older age;
- Finding the causes of irregular periods;
- Evaluating testicular function in male infants;
- Measuring the causes of missed or undescended testicles;
- Determining the reason for developing male traits (virilization), such as excessive hairiness, hoarseness, etc., in women.
Who Should Get an AMH Test?
Women under 38 who want to postpone their pregnancy should do an AMH test. If the test results show that the patient has a low ovarian reserve, the doctor will recommend she try getting pregnant as soon as possible. However, women over 40 have a poor ovarian reserve (POR) per se. Therefore, they are not often recommended to do the test.
Furthermore, people with a family history of ovarian failure, those with autoimmune diseases, those receiving chemotherapy, and women with past ovarian surgery are required to perform an ovarian reserve test.
When to Do the Ovarian Reserve Test?
Unlike Follicle-stimulating hormone (FSH), AMH does not vary during the menstrual cycle. Therefore, you can perform the AMH test anytime in the period cycle. Additionally, performing an ovarian reserve test does not require special conditions such as fasting. Furthermore, using contraceptive pills does not affect the result of the AMH test.
How is AMH test Done?
A laboratory blood test is done through superficial veins to test the AMH levels. AMH test is among the different tests for measuring ovarian reserve. The fertility doctor may recommend combining these tests for the final diagnosis.
What is the Normal Range of Ovarian Reserve?
The normal AMH level depends on the age of the patient. For example, the range of ovarian reserve that is normal for a 42-year-old woman may be a sign of early ovarian aging (EOA) in a 32-year-old woman.
The normal AMH levels in women who are under 35 years old are as below:
AMH Test Interpretation
more than 4 ng/mL
a bit lower than normal
less than 0.5 ng/mL
Interpreting Measures of Ovarian Reserve
Interpreting the results of the AMH or ovarian reserve test results helps determine the best time to get pregnant and the probability of fertility.
• Normal AMH level does not have an exact and specific range. However, an AMH level of less than 0.5 ng is usually an indicator of low ovarian reserve. In this case, a maximum of 2 to 3 follicles is obtained.
• AMH level between 0.5 and 1 ng/mL is a marker of low ovarian reserve. In this case, a low number of eggs is obtained.
• AMH level between 1-3.5 ng/mL indicates a normal range of ovarian reserve. This level suggests a good response to the treatment.
• AMH level of more than 3.5 5 ng/mL indicates a poor response to ovarian stimulation drugs. Therefore, doctors should use an appropriate dose of medications. However, the average hormone level fluctuates at different ages.
Male traits in women occur due to the presence of a tumor that produces the anti-müllerian hormone or the presence of undescended testes (cryptorchidism) in women's bodies. This condition is a rare genetic disease in which the testicles can be completely hidden or appear as ambiguous (uncertain) genitalia. Furthermore, in masculine women with an average level of Anti-Mullerian hormone, AMH is produced by the adrenal glands.
What is The Role of the Anti‐Mullerian Hormone in Diagnosing Female Fertility?
AMH levels can help measure female fertility. Pregnancy occurs when an egg is released by follicles and then moves to the uterus. Follicles are small sacs containing immature eggs found inside women's ovaries in large numbers.
These follicles are formed in the ovaries of baby girls from the embryonic stage, and many of them are destroyed at puberty. When a girl reaches puberty and begins menstruating, one egg matures monthly (approximately every 28 days) and, after splitting its follicle, moves to the uterus through one of the fallopian tubes (uterine tubes).
Pregnancy occurs when the matured egg is fertilized by sperm. Menstrual bleeding will begin after a few days if the egg is not fertilized. The role of the remaining immature follicles in the ovaries is crucial to measure female fertility. These follicles produce and secrete AMH by measuring which the amount of women's ovarian reserves can be determined.
What is the Role of the AMH Test as a Diagnostic Tool for PCOS?
The ovarian reserve test may also diagnose polycystic ovary syndrome (PCOS). Therefore, in case PCOS symptoms occur, one should see a doctor. These symptoms include persistent acne, menstrual disorders like amenorrhea or early menopause, unintentional weight gain, reduced breast size, hirsutism (abnormal hair growth on the face and body), etc. Very high AMH levels (Over 3.0 ng/ml) often are a sign of PCOS. If the patient is diagnosed with PCOS, she should do an AMH test. She may also perform other tests, such as ultrasound and hormonal tests.
What Factors Affect the AMH Test Result?
Several factors interfere with the AMH test results; however, each effect has not been determined. These factors include chemotherapy, radiation therapy, obesity, use of oral contraceptive pills, smoking, PCOS, ovarian surgery, preeclampsia, and ruptured ovary. The race factor is also effective in the results of the anti-Mullerian test.
What is the Correlation Between Anti-Müllerian Hormone and Age?
There is an inverse relationship between the AMH level and women's age. In other words, AMH levels gradually decline as the count and quality of eggs reduce with age. Women aged 20 to 30 have the highest count and quality of eggs (known as golden eggs). Almost from the age of 33, the count and quality of eggs decrease.
Young women with low egg counts and AMH still have a better chance of pregnancy than older women since the number and quality of eggs decline with age. However, young women with low counts of eggs still have higher quality eggs; therefore, they have a great chance of experiencing a successful pregnancy, especially through IVF.
Furthermore, older women with high AMH levels cannot expect a 100% successful IVF. The reason is that even with a high count of eggs, most of the eggs have low quality and may not lead to the production of healthy and strong embryos.
What is the Influence of AMH on IVF success?
The success of IVF depends mainly on the number and quality of retrieved eggs. The adequate ovarian reserve identified by high AMH levels increases the chance of IVF success. It is because the more and healthier eggs are obtained, the more likely the product of a healthy embryo in the lab and achieving a successful pregnancy.
With age, especially after 38, the egg count decreases, and most of them bear genetic abnormalities. This will increase the probability of IVF failure.
Therefore, a low AMH level can be a warning sign for the impossibility of retrieving many healthy eggs after ovarian stimulation in the IVF method. In general, AMH levels below one ng/ml may cause the following problems in IVF treatment:
- Decreasing the number of collected eggs during egg retrieval;
- Increasing the chance of abnormal fertilization;
- Increasing the risk of a canceled IVF cycle and inability to retrieve eggs.
Frequently Asked Questions about Ovarian Reserve Test
1) What is the normal range of ovarian reserve?
The normal ovarian reserve level depends on age. This level in a 35-year-old woman is between 1 to 3.5 ng/ml.
2) What causes high ovarian reserve?
A high AMH level shows a high chance of fertility. It is also one of the PCOS symptoms.
3) Does the AMH test require fasting?
No, the AMH test does not require fasting.
4) Is the AMH test affected by contraceptive pills?
No, it is not. As AMH is produced constantly by growing follicles in the ovary, its levels are not affected by contraceptive pills.
5) Do some diseases affect AMH test results?
Yes, some underlying disorders cause changes in the AMH test. Some of those conditions cause an increase, and others cause a decrease in the AMH level.
6) How do I know if my AMH is not normal?
Several symptoms indicate abnormal AMH levels. We can mention reduced breast size, acne, early menopause, hirsutism, weight gain, etc.