Anti-Müllerian Hormone Test

An anti-müllerian hormone (AMH) test measures the amount of AMH in a blood sample. In males, AMH is made by the testicles (or testes), which are glands that make sperm and male hormones. In females, the ovaries make AMH.

The ovaries are glands where eggs form and female hormones are made. AMH plays different roles in males and females and normal levels of AMH vary with your sex and your age. Measuring AMH levels can provide information about a variety of reproductive health conditions.

In unborn babies, AMH helps form the male and female reproductive organs. The sex of unborn babies is set by the chromosomes they inherit from their parents. Male babies have XY chromosomes and female babies have XX chromosomes.

But the development of their reproductive organs and genitals is affected by hormones, including AMH. In the early weeks of pregnancy, both male and female babies have a set of ducts (tubes) called Müllerian ducts. Normally, male babies make high levels of AMH in their testicular tissue.

The AMH makes the Müllerian ducts shrink and helps male organs to grow. AMH levels stay high in male children until puberty when they begin to decrease. Unborn female babies have very low levels of AMH.

This allows the Müllerian ducts to develop into the uterus, fallopian tubes, and the upper part of the vagina. AMH stays low in female children. At puberty, follicles inside the ovaries begin to make more AMH.

Follicles are small sacs in the ovaries that hold immature eggs. In healthy females of childbearing age, higher levels of AMH mean that the ovaries have a larger supply of eggs. As females age, the number of eggs decreases, which causes AMH levels to decrease.

At menopause, no eggs are left, and AMH levels drop to zero.

Why this test is done

If you're female, you may need an AMH test if you:

• Are having fertility problems. You may need an AMH test to:
• Find out if your egg supply is normal for your age.
• Plan in vitro fertilization (IVF) treatment. Higher levels of AMH mean that you're likely to respond to fertility medicine and you may only need a small dose. Low levels of AMH may mean need higher doses to respond.
• Have symptoms of polycystic ovary syndrome (PCOS), including:
• Irregular menstrual periods, or no periods at all (amenorrhea)
• Acne
• Too much hair on the face, chest, stomach, or thighs
• Hair loss on the head (male pattern baldness)
• Weight gain
• Dark patches of skin
• Are being treated for certain types of ovarian cancer. AMH testing can show if your treatment is working. After treatment the test can show whether cancer has returned.

A male baby or child who doesn't have testicles in the scrotum may need an AMH test to help find out if there are healthy testicles inside the body.

A baby with genitals that aren't clearly male or female may need an AMH test along with other tests to help diagnose the cause of the disorder and confirm the sex.

How to prepare

You don't need any special preparations for an AMH test.

Sample type

Blood

Other names for this test

AMH hormone test, müllerian-inhibiting hormone, MIH, müllerian inhibiting factor, MIF, müllerian-inhibiting substance, MIS