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.