Is the AMH Test Reliable?

The AMH Test has traditionally been considered to be a reliable indicator of fertility or has it?  There has been recent media coverage that throws doubt on the AMH test, sometimes referred to as the ‘egg-timer test’ and whether it is worth doing at all.

What is AMH?

Anti-Mullerian hormone, also known as AMH, can be measured by a blood test. AMH is released from the total pool of eggs left in the ovaries.

A woman is born with all the eggs she will ever have. These eggs decline in number with age and so does the AMH level. The level of a woman’s AMH level can be compared with the range expected for her age.

There is only a slight variation in the hormone level when tested in different parts of the menstrual cycle so the test can be performed at any time.

The levels are reasonably reliable for most women whilst on the oral contraceptive pill which can sometimes artificially suppress the level of AMH by up to 17%. There has been reported variation in results from different pathology departments and this has been one of the reasons for recent criticisms of the test.

AMH is very often considered to be a ‘fertility test’, when in reality, it is a ‘screening test’.  It is a useful indicator of the number of eggs remaining, rather than the quality of those eggs.

A low AMH result does not mean that the person is infertile. It is simply one of many screening tests to help uncover and treat a fertility problem. 

The AMH test is useful when performed by an experienced laboratory but needs to be interpreted in context of the clinical situation.  The test shows how proactive you need to be about fertility, in conjunction with your age. 

What the AMH test can’t do

Recently, there has been some debate about who should have this screening test. A woman who undertakes the test, even though she is not trying to conceive may find herself in a dilemma. A test result that is not in the normal range for her age may cause considerable concern.   Much of this worry is  unnecessary.

The real problem with both AMH is that it doesn’t help to assess egg quality or the quality of the ovaries.  In this case, a woman may need a scan to assess the quality of the ovaries, the and also stimulation medication, in the form of IVF, to see how her ovaries respond. 

While AMH is a good baseline screening test, there will be many women that have very low AMH levels but conceive in their first month of trying.

For the unsuspecting woman that has not even tried to conceive and discovers an alarmingly low result, there may be a benefit. It is to highlight the importance of making plans to have a baby.

One of the risks of finding a normal result however, is that a woman may be falsely reassured that her fertility is ok and delay a family for longer. Even women in their mid-40s can have a high result sometimes. But those eggs have been around for a long time, exposed to the same ageing process that affects the rest of our bodies. Therefore it gets harder to get pregnant and stay pregnant as a woman gets older.

How can AMH Results be Helpful?

An AMH level can be a useful tool for a fertility specialist planning treatment. It can guide clinicians on the dose and regimen of treatment, as well as give an indication of the likely egg number range a woman might achieve with IVF.

However, an ultrasound scan might be just as good for this purpose. A doctor might predict a high or low egg number with IVF based on these tests.

This is not a perfect science as each month is different and each woman’s response to treatment can vary. The number of eggs obtained is not the main focus, it’s the quality that counts.

There is no good test for egg quality.

The test result should be part of an overall assessment of a woman’s chances of conceiving. An ultrasound scan is a very useful test to do. The ovarian reserve, or total number of eggs, can be inferred by the number of baseline follicles seen on an ultrasound. The ultrasound adds support to the results of the AMH level in most cases.

We really need to talk about these results in the context of all the other fertility factors for an individual. Included in this are their plans for the future:

• Have they been trying to conceive?
• For how long?
• Are they planning more than one child?
• Have they got a partner?
• Should we be considering egg freezing?
• Is there a family history of early menopause?
• Should they bring forward their plans to have a baby?

The main message needs to be that an AMH is one of many bits of information that builds a picture. It is not a test for egg quality, only quantity. It should be performed by someone who is knowledgeable on the pros and cons of the test so that when that result arrives, it can immediately be put into context for you.

We cannot predict reliably when your eggs will run out. Female age is a better predictor of egg quality than AMH. A low result does not mean your fertile days are over. Just ask all the women out there that had low ovarian reserve and are now holding their babies.