What is AMH?

AMH stands for Anti-Müllerian Hormone. It is also called MIS (Müllerian Inhibiting Substance). Since AMH is produced directly by the ovarian follicles, AMH levels correlate with the number of antral follicles in the ovaries. It has been documented that women with lower AMH have lower antral follicular counts and produce a lower number of oocytes compared with women with higher levels.

AMH Reference ranges

Interpretation:

AMH levels do not change significantly throughout the menstrual cycle and decrease with age. Healthy women, below 38 years old, with normal follicular status at day 3 of the menstrual cycle, have AMH levels of 2.0 – 6.8 ng/ml   (14.28 – 48.55 pmol/L). High levels are found in patients with PCOD.

Ovarian Fertility Potential         pmol/L              ng/mL

Optimal Fertility                            28.6 - 48.5          4.0 - 6.8

Satisfactory Fertility                    15.7 - 28.6           2.2 - 4.0

Low Fertility                                    2.2 - 15.7             0.3 - 2.2

Very Low / undetectable           0.0 - 2.2               0.0 - 0.3

High Level                                        > 48.5                  >6.8

AMH levels do not vary with the menstrual cycle and can be measured independently of the day of the menstrual cycle.

AMH can be used for

1.       Evaluating Fertility Potential and ovarian response in IVF – Serum AMH levels correlate with the number of early antral follicles. This makes is useful for predicting your ovarian response in an IVF cycle. Women with low AMH levels are more likely to be poor ovarian responders.

2.       Measuring Ovarian Aging – Diminished ovarian reserve, is signaled by reduced baseline serum AMH concentrations. Women with poor ovarian reserve who have entered the oopause have low levels of AMH. However, this is a new test, and is still not easily available.

The old standard for ovarian reserve testing was the Day 3 FSH level.

However, the FSH level is not as reliable as the AMH level for 3 reasons.

1.       The FSH level varies according to the cycle dates

2.       It depends upon the estradiol level ( a high estradiol level will artificially suppress a high abnormal FSH level into the normal range)

3.       It varies from cycle to cycle, so is not always reliable or dependable

An AMH level is a much better marker for ovarian reserve. It is much more stable than the FSH level and does not vary from cycle to cycle. Even better, it can be measured on any day of the cycle! This is why most infertility specialists today use AMH to check ovarian reserve, rather than the old FSH level.

One confusing thing about AMH is that there are at least 2 scales out there and innumerable clinic definitions of what is "normal" - it depends on which assay they use and which study!  One scale is ng/ml and one is pmol/l.  The pmol/l scale runs from 0 to about 48; the ng/ml runs from about 0-10.  On the ng/ml scale, less than 2ng/ml is considered to be low. 

An AMH level can also be very useful for young women who want to postpone childbearing and want to check their fertility. Many women these days are postponing having a baby in order to pursue a career. The good news is that while usually fertility does not decline too much until the age of 32, for some women the decision to postpone childbearing can prove to be one they bitterly regret later on. Fertility does decline as a woman grows older, and the problem is that it is not possible to predict the rate of decline for an individual woman. Most women are lulled into a false sense of security if they have regular period, because they assume that if their periods are regular, this automatically means that their egg quality if enough for them to make babies!