AMH (Anti-Müllerian Hormone): Ovarian Reserve Test Explained
AMH gives the best single-number estimate of ovarian reserve — but does not predict natural fertility. Learn what a low, normal, or high AMH really means.
AMH reflects the size of the ovarian follicle pool. Values fall with age — from ~4–6 ng/mL in the mid-20s to < 1 ng/mL near menopause. AMH is useful for predicting IVF response and supporting a PCOS diagnosis, but it is a poor predictor of natural fertility. A low AMH does NOT mean you cannot conceive naturally.
AMH is produced by granulosa cells of small growing follicles and gives the best available estimate of ovarian reserve — the size of the remaining follicle pool. Values decline with age; menopausal AMH is < 0.1 ng/mL. High AMH (> 5 ng/mL) supports PCOS diagnosis (Rotterdam criteria include AMH as an ultrasound-alternative in updated 2023 international guideline). Low AMH predicts poor IVF response and helps individualise stimulation protocols. Crucially, AMH does NOT predict natural pregnancy chance in women trying to conceive — cycle-based fertility is preserved until close to menopause. Ordering AMH for reassurance about natural fertility risks anxiety without benefit.
- Best use
- Ovarian reserve for IVF; PCOS diagnosis
- Poor predictor of
- Natural conception
- Menopausal AMH
- < 0.1 ng/mL
- PCOS support
- AMH > 5 ng/mL
- Cycle timing
- Any day — no cycle dependence
AMH by age (approximate reference range)
AMH varies widely, but typical central values by age: 25 y ~4–6 ng/mL, 30 y ~3–5, 35 y ~2–4, 40 y ~0.8–2, 45 y < 1. Ethnicity, smoking, and BMI shift the curve. Interpret with clinical context, not against a single cut-off.
AMH categories and interpretation
| AMH (ng/mL) | Category | Meaning |
|---|---|---|
| < 1 | Low | Diminished ovarian reserve; poor IVF response predicted |
| 1 – 3.5 | Normal | Typical for age 30–40 |
| > 3.5 | High | Good IVF response predicted; investigate PCOS |
| > 5 | Very high | Supports PCOS diagnosis |
When AMH is worth testing
IVF planning: predicts ovarian response and guides gonadotrophin dose to minimise hyperstimulation.
Suspected PCOS: 2023 International PCOS Guideline allows AMH as an alternative to ultrasound follicle count for the "polycystic ovarian morphology" criterion (in adults, > 3 years post-menarche).
Fertility preservation counselling before chemotherapy or ovarian surgery.
Suspected premature ovarian insufficiency (persistently low AMH + elevated FSH + irregular periods).
When AMH is misleading
General fertility screening in women trying naturally: AMH does NOT predict natural monthly pregnancy chance. A woman with AMH 0.8 can still conceive naturally; a woman with AMH 5 has no guarantee. Age remains the strongest single predictor.
On hormonal contraception: some formulations suppress AMH by 20–30%. Interpret cautiously.
- Persistently low AMH + irregular or absent periods in a woman < 40 — premature ovarian insufficiency workup.
- Very high AMH + irregular cycles + hirsutism or acne — PCOS diagnostic workup.
- AMH concerning + trying to conceive > 6 months at age > 35 — fertility referral.
AMH workup
- 1Planning IVF?AMH guides stimulation protocol.
- 2Suspected PCOS?AMH > 5 supports diagnosis alongside cycle irregularity and hyperandrogenism.
- 3Trying naturally?AMH is not helpful. Focus on age, cycle regularity, partner semen analysis.
- 4Low AMH + irregular periods < 40?FSH, oestradiol, TSH, prolactin. Endocrinology or fertility referral.
Related questions people ask
- Does AMH predict natural fertility?
- What is a normal AMH by age?
- Is AMH useful for PCOS diagnosis?
- Does contraception affect AMH?
- How is TSH related to fertility?
- What about thyroid antibodies in fertility?
- How does male testosterone relate to fertility?
Frequently asked questions
- AMH reflects ovarian reserve, not natural fertility.
- Falls with age — under 1 ng/mL is diminished reserve.
- Above 5 ng/mL supports PCOS.
- Best use: IVF planning + PCOS diagnosis.
- Cycle day does not matter.
- Do not use AMH to reassure or scare women trying naturally.
References
3 sources- ESHREOvarian Stimulation Guidelines
European fertility society.
eshre.eu
- ASRMTesting and Interpreting Measures of Ovarian Reserve
US fertility society.
asrm.org
- International PCOS Guideline 2023
PCOS diagnostic consensus.
monash.edu
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