What is an Anti-Mullerian Hormone (AMH) test?

This test measures the level of Anti-Mullerian 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.

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. Women are born with their lifetime supply of eggs, but these decrease with age. 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. 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. We may use the test to predict whether you will respond well to treatment, such as ovulation induction / stimulation. Normal 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

• Acne

• 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 do the results mean?

If you are 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).

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 who have not started their menses and in women after menopause.

If you are being treated for ovarian cancer, your test can show whether your treatment is working.