Most women I see have already Googled their AMH before they get to me. The number came back, it sat below a range on a page, and by the time we speak they’ve read that their eggs are running out and they should hurry. That’s a horrible few days to sit through, and quite often it isn’t what the result is telling them.
So here’s what the number is, and what it takes to read it properly.
What AMH is measuring
Anti-Müllerian hormone is made by the small follicles in your ovaries. Measuring it gives a rough estimate of how many came forward in that particular cycle. That last part matters, because the figure isn’t fixed. It shifts month to month depending on how many follicles were recruited, and plenty of ordinary things move it: stress, a recent illness, nutrient and mineral deficiencies.
Two conditions skew it further. PCOS tends to push AMH up, because there are more small follicles sitting there, so a result can read high while ovulation isn’t happening reliably. Endometriosis tends to pull it down. In both cases the number is describing something other than what people assume it is.
Which means a single reading can be a quiet month, or a skewed one, rather than a true picture of your ovarian reserve. It’s a headcount taken on one day, and it says nothing at all about the quality of the eggs you have.
Clinics use AMH to anticipate how you might respond to stimulation, and it’s the best marker available for that. But one reading is a thin basis for a decision that size, which is why I’d want more than one before anybody draws conclusions from it.
Where it gets misinterpreted
Usually the problem starts with a lab flag and a short appointment. A GP who doesn’t work in fertility or hormones sees a result marked low and reasonably enough reads it as low egg reserve. What doesn’t get explained is everything above: that the number moves each cycle, that illness or stress or a nutrient deficiency could have pulled it down that month, and that one test is a snapshot rather than a verdict.
So a woman leaves with the impression she’ll struggle to conceive naturally. Sometimes that pushes her toward IVF earlier than she needed to go.
The research is more cautious than the conversation usually is. Studies have found AMH to be a weak predictor of natural pregnancy, and the authors warned specifically about over-interpreting it in preconception counselling and creating unnecessary fertility anxiety. That caution rarely makes it as far as the woman holding the result.
The number moves
Your AMH isn’t a fixed figure. It changes cycle to cycle with the follicles that come forward, and it moves within a single cycle too, where researchers sampling healthy women every second day found the variation inside one cycle was larger than the variation between cycles.
So when someone wants a number they can rely on, I’ll usually suggest three tests across six cycles. That way we’re reading a trend rather than a single day, and we know we haven’t simply caught a quiet month. It still isn’t the whole story, and it’s a good deal more reliable than one result taken at a random point.
How to read a low result
A low AMH means fewer follicles came forward. It doesn’t tell you the ones you have are poor, and it doesn’t tell you this month won’t work. Plenty of women with low AMH conceive without help, and age remains a stronger predictor of egg quality than AMH ever was.
This is one of my favourite conversations to have, because the relief in the room is immediate once someone understands what they’re actually looking at.
What I look at alongside it
One hormone on one day is thin evidence for a decision this big. AMH is worth reading next to the other reproductive markers rather than on its own. For example, FSH and LH show how hard your body is working to recruit follicles, which is a different question from how many are sitting there. Progesterone in the second half of the cycle confirms ovulation actually happened. And if you have a partner, a sperm analysis, because that’s half the picture and it’s usually the half nobody has looked at.
Then the background markers, because they all affect cycles and all four are cheap to check: thyroid, iron, vitamin D and B12. And how regular things have been across the last year rather than the last month.
Results that came back “normal” can still deserve a second read, because reference ranges are broad and the overall picture matters more than any single number sitting inside its bracket. That applies just as much to a number sitting outside one.
If your result was low
A few things genuinely change the odds over the following three months, and none of them involve panic. Egg quality responds to the roughly ninety days before ovulation, so sleep, alcohol and nutritional status across that window are worth attention. Get the repeat tests done rather than deciding off the first one. And if your partner hasn’t been tested, start there, because it’s the quickest way to fill in the missing half.
If you’re weighing up IVF or egg freezing, that decision deserves more than one AMH reading behind it. A trend across a few cycles, read next to your FSH, LH, progesterone and a sperm analysis, tells you something useful. A single figure on its own doesn’t.
If you’ve had bloods done and want to understand what they’re actually saying before you make any decisions, that’s exactly what my fertility naturopathy consultations are for. Bring whatever you have, including the results that came back “normal”.