What does an AMH test actually measure?

Anti-Müllerian hormone (AMH) is produced by small follicles in the ovaries and reflects ovarian reserve — the remaining pool of eggs. Higher levels broadly suggest more follicles remaining; lower levels suggest fewer. AMH is a legitimate tool in IVF clinics for predicting ovarian response to stimulation — where dose titration matters, it has genuine clinical utility. The problem is its use outside that context: as a general fertility check, a predictor of natural conception likelihood, or a guide to life decisions. In those applications, the evidence is poor. AMH does not reliably predict the chance of natural conception in healthy women without a specific clinical indication.

Should I ask my GP for an AMH test?

It depends on why you are asking. If you are being referred for IVF or egg freezing and your specialist wants to calibrate stimulation, AMH is appropriate. If you are a healthy woman who wants to know your fertility status without a specific clinical indication, the evidence does not support AMH as a reliable tool for that purpose. The Flinders study found that 20% of women received a low result — but one-third of those who retested showed normal ranges. A low result from a single test can cause significant distress and drive major decisions around egg freezing, relationships, and timelines — without providing reliable predictive information. Discussing what you are actually trying to know with your GP before ordering the test is worth doing.

The fertility test your GP orders 13 times more than a decade ago

What just happened

A Flinders University study of nearly 1.4 million Australian women has found that requests for anti-Müllerian hormone (AMH) testing in general practice rose 13-fold between 2011 and 2021. In women aged 30 to 34, the increase was nearly 20-fold. The RACGP’s newsGP reported this week that the researchers concluded most of this testing does not appear to be evidence-based.

Associate Professor Luke Grzeskowiak, who led the study, was direct: “It cannot tell a healthy woman how likely she is to conceive, how quickly, or how much reproductive time she has left.” The test has migrated from its original home — IVF clinics calibrating ovarian stimulation — into general practice, driven by a convergence of delayed childbearing, rising fertility anxiety, social media influence, and commercial promotion.

The researchers found that approximately 20% of women tested received a low AMH result. One-third of those who retested subsequently showed normal ranges. That variability is not a minor technical footnote. It means women are making significant, sometimes irreversible decisions — about egg freezing, about relationships, about their timelines — on the basis of a single number that can change on retest.

Both-and

The legitimate use case

AMH has a genuinely useful application. In the context of IVF, measuring ovarian reserve allows clinicians to adjust gonadotropin doses to avoid both under-response (no eggs collected) and over-response (ovarian hyperstimulation syndrome). For that purpose — titrating medication in a supervised assisted reproduction cycle — AMH is a reasonable, evidence-supported tool.

The problem is function creep. Once a test exists, its uses tend to expand beyond the validated indication. AMH is now marketed to healthy women as a “fertility check” or “ovarian age” test. Fertility clinics and direct-to-consumer testing companies advertise it as insight into your biological clock. General practice has started ordering it in response to patient request, social media influence, and genuine clinical uncertainty about how to respond to a worried 32-year-old.

That clinical uncertainty is real. When a patient asks whether she needs to think about her fertility timeline, “we don’t have a reliable test for that” feels like a non-answer. The existence of a number — even an unreliable one — is more comfortable than the uncertainty that actually exists.

What the system is producing

Australia’s total fertility rate reached a historic low of 1.481 births per woman in 2024, continuing a multi-decade decline below replacement level. Australians are having children later, more are using assisted reproduction, and fertility anxiety — the fear of leaving it too long — is culturally active in a way it was not a generation ago.

That anxiety is real and deserves to be met with something. The problem is that the something being offered — a single AMH number — does not reliably map onto what the patient is actually asking. She is asking: will I be able to have a baby? AMH does not answer that. A low AMH result in a healthy woman with regular cycles and no other indicators has a weaker relationship with natural conception rates than most patients, and some GPs, assume. A normal result does not protect against infertility caused by blocked tubes, partner factors, or an underlying condition the test does not measure.

What the system is producing is a cohort of women who received a low result, were appropriately distressed, and made significant decisions — some of which they would not have made with better information about what the number means. Others received normal results and assumed reassurance that was not warranted. Neither group was well served.

What evidence-based practice looks like here

The researchers are calling for evidence-based clinical guidelines on appropriate AMH testing indications. That is the right call. The conversation a patient needs when she asks about her fertility is not “here is your AMH number.” It is a more honest conversation about what the evidence does and does not show, what factors actually predict natural conception probability, and what the realistic pathways are if she is concerned.

That conversation is harder. It takes longer. It involves sitting with uncertainty rather than handing over a number. But it is what the evidence supports.

2 cents

If you have had an AMH test and received a result that worried you — or reassured you — it is worth understanding what that number actually represents. A single AMH result is not a crystal ball for your reproductive future. It reflects ovarian reserve (the remaining follicle pool), not fertility in the sense most women mean when they use that word.

If you are considering having your AMH tested, the question worth raising with your GP is: what would we do differently depending on the result? If the answer is “refer you to a fertility specialist,” then asking directly whether a referral is warranted may be a more efficient path than ordering the test first.

This is not an argument against knowing your body or seeking information. It is an argument for seeking information that is actually informative.

This is general information. For a conversation about your specific situation, your GP is the right starting point.

Verdict: yes — worth knowing about. The 13-fold rise in AMH testing is a signal that something in the system is not working for women trying to make decisions about their reproductive futures.