What is an anti-müllerian hormone (AMH) test?
This test measures the level of anti-müllerian hormone (AMH) in the blood. AMH is made in the reproductive tissues of both males and females. The role of AMH and whether levels are normal depend on your age and gender.
AMH plays an important role in the development of sex organs in an unborn baby. During the first weeks of pregnancy, a baby will start developing reproductive organs. The baby will already have the genes to become either a male (XY genes) or a female (XX genes).
If the baby has male (XY) genes, high levels of AMH are made, along with other male hormones. This prevents the development of female organs and promotes the formation of male organs. If there is not enough AMH to stop the development of female organs, organs of both sexes may form. When this happens, a baby’s genitals may not be clearly identified as male or female. This is known as ambiguous genitalia. Another name for this condition is intersex.
If the unborn baby has female (XX) genes small amounts of AMH are made. This allows for the development of female reproductive organs. AMH has a different role for females after puberty. At that time, the ovaries (glands that make egg cells) begin making AMH. The more egg cells there are, the higher the level of AMH.
In women, AMH levels can provide information about fertility, the ability to get pregnant. The test may also be used to help diagnose menstrual disorders or to monitor the health of women with certain types of ovarian cancer.
Other names: AMH hormone test, müllerian-inhibiting hormone, MIH, müllerian inhibiting factor, MIF, müllerian-inhibiting substance, MIS
What is it used for?
An AMH test is often used to check a woman’s ability to produce eggs that can be fertilized for pregnancy. A woman’s ovaries can make thousands of eggs during her childbearing years. The number declines as a woman gets older. AMH levels help show how many potential egg cells a woman has left. This is known as the ovarian reserve.
If a woman’s ovarian reserve is high, she may have a better chance of getting pregnant. She may also be able to wait months or years before trying to get pregnant. If the ovarian reserve is low, it may mean a woman will have trouble getting pregnant, and should not delay very long before trying to have a baby.
AMH tests may also be used to:
- Predict the start of menopause, a time in a woman’s life when her menstrual periods have stopped and she can’t become pregnant anymore. It usually starts when a woman is around 50 years old.
- Find out the reason for early menopause
- Help find out the reason for amenorrhea, the lack of menstruation. It is most often diagnosed in girls who haven’t started menstruating by the age of 15 and in women who have missed several periods.
- Help diagnose polycystic ovary syndrome (PCOS), a hormonal disorder that is a common cause of female infertility, the inability to get pregnant
- Check infants with genitals that are not clearly identified as male or female
- Monitor women who have certain types of ovarian cancer
Why do I need an AMH test?
You may need an AMH test if you are a woman who is having difficulty getting pregnant. The test can help show what your chances are of conceiving a baby. If you are already seeing a fertility specialist, your doctor may use the test to predict whether you will respond well to treatment, such as in vitro fertilization (IVF).
High levels may mean you may have more eggs available and will respond better to treatment. Low levels of AMH mean you may have fewer eggs available and may not respond well to treatment.
You may also need an AMH test if you are a woman with symptoms of polycystic ovary syndrome (PCOS). These include:
- Menstrual disorders, including early menopause or amenorrhea
- Excess body and facial hair growth
- Decreased breast size
- Weight gain
In addition, you may need an AMH test if you are being treated for ovarian cancer. The test can help show if your treatment is working.
What happens during an AMH test?
A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
Will I need to do anything to prepare for the test?
You don’t need any special preparations for an AMH test.
Are there any risks to the test?
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
What do the results mean?
If you are a woman trying to get pregnant, your results can help show what your chances are for conceiving. It can also help you decide when to try to get pregnant. A high level of AMH can mean your chances are better and you may have more time before trying to get pregnant.
A high level of AMH may also mean you have polycystic ovary syndrome (PCOS). There is no cure for PCOS, but symptoms can be managed with medications and/or lifestyle changes, such as maintaining a healthy diet and waxing or shaving to remove excess body hair.
A low level can mean you may have trouble getting pregnant. It can also mean that you are starting menopause. A low level of AMH is normal in young girls and in women after menopause.
If you are being treated for ovarian cancer, your test can show whether your treatment is working.
In a male infant, a low level of AMH may mean a genetic and/or hormonal problem causing genitals that are not clearly male or female. If AMH levels are normal, it may mean the baby has working testicles, but they are not in the right location. This condition can be treated with surgery and/or hormone therapy.
If you have questions about your results, talk to your health care provider.
Is there anything else I need to know about an AMH test?
If you are a woman being treated for fertility problems, you will probably get other tests, along with AMH. These include tests for estradiol and FSH, two hormones involved in reproduction.