Anti-Mullerian Hormone (AMH)
AMH is a growth factor hormone. AMH was originally identified as the factor in males that causes the fetal female sexual organs to disappear. We believe it’s role is to prevent follicles from growing. Animal research showed us that without AMH the follicles containing eggs are used up quickly.
- AMH indirectly reflects the number of remaining eggs in the ovary. The growing antral follicles (secrete the hormone).
- Low anti-mullerian hormone means low egg numbers. Low levels may be useful to predict the age of menopause or the need for extra stimulation medication for infertility treatment.
- High AMH indicates high egg numbers and high sensitivity to stimulation medication. Women with high egg numbers are at higher risk of ovarian hyperstimulation (OHSS).
Where does the hormone come from?
AMH is produced by the granulosa cells from the antral follicles in the ovary. Follicles are the structures that surround the eggs. The preantral follicles cannot be seen with ultrasound. The antral follicles contain cystic areas that are visible to ultrasound (the antral follicle count – AFC).
AMH blood levels reflect the number of growing follicles. The number of growing follicles are related to the number of eggs. Therefore, Anti-Mullerian Hormone levels are a means of determining the number of remaining eggs in the ovary.
In the graphic above:
- The follicle progresses through stages until it releases an egg. Recall that about 500-1000 eggs start development but a single egg ovulates.
- Notice that the early follicles progressively produce AMH. At the antral follicle stage, FSH stimulates further growth and overcomes the inhibition of cell growth by AMH.
- FSH promotes the continued development of the antral follicles and the follicle most receptive to FSH’s effects is the one that ovulates.
AMH seems to be stable from day-to-day and month-to-month in a cycles from women of all ages. We can draw your blood for AMH on any cycle day. The values are affected by taking gonadotropin medications therefore we do not measure while on treatment. It has become a new marker for ovarian reserve (fertility potential).
The following graphs show the changes in Anti-Mullerian Hormone levels through the years. Please note the variability present but the clear trend to lower numbers with age.
Can the hormone levels be used to predict menopause?
The following chart of information helps us understand how to use AMH to predict the age of menopause.
AMH can also be used to help us avoid OHSS (Ovarian Hyperstimulation Syndrome) because women with very high levels are at greater risk of OHSS.
- AMH reflects the number of remaining eggs in the ovary
- Low AMH means low egg numbers and may be useful in predicting menopause and suggests the need for extra stimulation medication
- High AMH indicates sensitivity to stimulation medication and higher risk of OHSS