The Anti-Mullerian hormone (AMH) test also known as the Mullerian Inhibiting Substance (MIS) test, is a measure for determining the number of fertile eggs left in a woman. The test mainly measures the approximate amount of ovarian reserve that is present in a woman.
When a female child is born, she is born with all the eggs that she will produce in her whole life time. This collection of eggs present in the ovary is known as the ovarian reserve. As the age increases, the number of egg keep on diminishing and finally at the stage of menarche ( start of menstrual cycle) one egg per month is discarded.
Therefore over time, the number of eggs keeps on diminishing. Thus the AMH test gives an approximation of the number of eggs left. The eggs are present in an egg sac that is known as a follicle. These eggs release an Anti-Mullerian hormone that is released into the bloodstream.
The level of AMH present in the blood is proportional to the number of eggs left in the ovarian reserve. During a menstrual cycle the level of AMH does not change, therefore blood can be drawn at any time of the month.
The level of AMH determines the quantity of the eggs and therefore helps in calculating the number of fertile years a person may have left. However, the quality of the eggs cannot be described through the test results. For calculating the number of fertile eggs left, the data is compared with the data women of the same age.
The AMH test is quite useful for people who want to conceive a baby and want to check if their ovarian reserve is inconsistent with the age. Women who are considering IVF and other fertility response should definitely get their AMH level checked. As a low AMH level could indicate a poor response to the IVF.
AMH levels are also indicative of an ovarian tumour or any damage that has been caused due to
medications like chemotherapy or ovarian surgeries. As AMH is produced by the granulosa cells that are present as the lining of the ovarian follicles, therefore, number of antral follicles that are present in the ovary can be determined by them.
It has been observed that women with high level of AMH have large a number of antral follicles
and therefore produce a huge number of oocytes. A woman who is below the age of 38 and is of normal health show an AMH level of 2.0 – 6.8 ng/ml. If anyone shows a level higher than this, then that may be indicative of PCOD ( polycystic ovary disorder).
The AMH levels are generally measured in two scales. Both the scales depend upon the type of assay used to perform the test. The ng/ml and pmol/ml are the two scales of measurement. The range of the ng/ml scale is from 0 to 10. While the range of the pmol/ml scale is from 0 to 48. With the ng/ml scale in use, a value of less than 2 ng/ml indicates a low level of AMH or we can say a low number of eggs left in the ovarian reserve.
Earlier to determine the fertility level of a person, the FSH (follicle stimulating hormone) levels were determined. But as FSH levels vary with the ongoing menstrual cycle and also depend on the level of estradiol, therefore they were not always dependable. The invent of AMH test made it easier and more specific and is thus preferred over the FSH test to calculate fertility levels.