AMH and FSH: What Fertility Hormone Tests Actually Tell You

AMH testing is marketed heavily as a way to check your fertility, and that framing is misleading in an important way. AMH gives a reasonable estimate of how many eggs remain — it says very little about your chance of conceiving naturally. Understanding what these markers actually measure prevents both false alarm and false confidence.

What each marker measures

AMH and antral follicle count measure the same underlying thing by different means, and they are usually interpreted together. Where they disagree, the ultrasound often carries more weight.

What AMH genuinely tells you — and what it does not

AMH is produced by small developing follicles, so the level tracks how many remain. It is stable across the cycle, which makes it convenient, and it declines with age.

Here is the part that marketing tends to skip. Studies in women without known infertility have consistently found that AMH does not predict how long it takes to conceive naturally. Women with low AMH for their age conceive at broadly similar rates to those with normal levels. Reserve is about quantity; conception depends far more on egg quality, which tracks age and which no blood test currently measures.

So a low AMH in a woman in her early thirties with regular cycles is not the emergency it is often presented as. It is a data point about reserve, not a verdict on fertility.

FSH, and why timing decides everything

FSH is the signal the pituitary sends to recruit a follicle each month. As reserve falls, the ovaries respond less readily and the pituitary compensates by sending more — so a rising FSH suggests declining reserve.

It only means anything on days two to five of the cycle, and only alongside oestradiol. A raised oestradiol can suppress FSH into the normal range, producing a falsely reassuring result. An FSH taken at a random point in the cycle, or reported without oestradiol beside it, is close to uninterpretable.

A persistently raised FSH in a woman under 40 with absent or irregular periods raises the possibility of early menopause, which we cover in menopause and perimenopause .

When these tests are worth doing

• Trying to conceive for twelve months without success — or six months if you are over 35.
• Considering IVF or egg freezing — this is where AMH earns its place most clearly.
• Periods that have become irregular or stopped before 40 — early menopause needs excluding.
• Before chemotherapy or ovarian surgery — a baseline informs decisions about fertility preservation.
• Investigating suspected PCOS — as supporting context alongside androgens and ultrasound.

In PCOS, AMH is often markedly raised because there are many small follicles — which is a sign of the condition rather than of good fertility. We cover this in PCOS, fibroids or endometriosis .

The half of the picture that gets skipped

Male factors contribute to roughly four in ten cases of infertility, either alone or alongside female factors. Despite that, testing frequently begins and sometimes ends with the woman.

A semen analysis is inexpensive, non-invasive and fast. If a couple has been trying without success, running it early is simply sensible sequencing — there is no good reason to complete a full female hormonal workup before checking something that accounts for a comparable share of cases.

What else is worth checking

Several treatable conditions affect fertility and are easily missed if attention stays fixed on ovarian reserve:

• Thyroid function — both underactive and overactive thyroid disrupt ovulation, and both are straightforward to treat.
• Prolactin — when raised, it suppresses ovulation. A common and correctable cause.
• HbA1c and insulin — insulin resistance affects ovulation, particularly in PCOS.
• Vitamin D, iron and B12 — all common deficiencies locally, and all relevant to a healthy pregnancy.

We set out how these systems fit together in hormonal imbalance symptoms: which system, and which test .

At HDC Medical, screening is dietitian-led, and the nutritional and metabolic groundwork — thyroid, iron, vitamin D, insulin sensitivity — is the part most often overlooked while attention sits on reserve markers. A hormone test is run where it is genuinely informative, and interpreted alongside the rest of your health screening .

This article is for general education and does not replace personalised medical advice. Reference ranges vary between laboratories — always interpret your results with a qualified professional. Blood screening is a monitoring and early-flag tool, not a diagnosis. HDC Medical is a dietitian-led health screening centre in Oval Damansara, Kuala Lumpur.