Anti-Müllerian Hormone (AMH) Unit Converter
Anti-Müllerian Hormone (AMH) Unit Converter
Convert AMH between ng/mL, µg/L and pmol/L — and read the result for what it is: an estimate of how many follicles are left, measured on an assay that cannot be swapped for another, and a poor predictor of whether you will conceive naturally.
Anti-Müllerian Hormone (AMH) converter
Mass ⇄ molarAMH 2.0 ng/mL in a woman aged 32
The conversion, and why the molar figure is a convention
ng/mL = pmol/L ÷ 7.14286
because 7.14286 = 1 ng/mL (10⁻⁶ g/L) ÷ 140,000 g/mol, the mass of the AMH dimer
- ×7.14 and ÷7.14
- the two numbers worth memorising. 1 ng/mL is 7.14 pmol/L; 10 pmol/L is 1.4 ng/mL. UK and European laboratories report pmol/L, North American ones ng/mL, and a result quoted without units is ambiguous by a factor of seven
- ng/mL = µg/L
- numerically identical — no conversion needed between them
- MW 140,000
- AMH is a disulphide-linked homodimeric glycoprotein of the TGF-β superfamily. It circulates as a mixture of the uncleaved precursor and cleaved N- and C-terminal fragments, so “moles of AMH” is a convention rather than a physical measurement — but 7.14 is the factor every laboratory and every published nomogram uses, so it is the one to use
- the conversion is not the problem
- converting units is exact. What is not exact is comparing results between assays: the Beckman Coulter, Roche Elecsys and other automated platforms are calibrated differently and are not interchangeable, and differences of a third or more between methods on the same serum have been reported. A change of laboratory can look like a change in ovarian reserve
Worked example
AMH 2.0 ng/mL in a woman aged 32
2.0 ng/mL = 2.00 µg/L — identical units, nothing to calculate
2.0 × 7.14286 = 14.29 pmol/L
Against Mayo's Elecsys interval for 30–34 years, 0.58–8.1 ng/mL (4.14–57.86 pmol/L), that is within range and towards the lower half
The single most useful conversion to remember: 1 ng/mL = 7.14 pmol/L, so a UK report of 14.3 pmol/L and a US report of 2.0 ng/mL are the same result
Two things could move this number without the ovary changing at all. If she is taking the combined oral contraceptive, her AMH is running roughly a quarter lower than it would otherwise — so the off-pill value might be nearer 2.7 ng/mL. And if last year's 2.6 ng/mL was measured on a different platform, the apparent fall may be the assay rather than her
What AMH does and does not predict
| Question | How well AMH answers it | Why |
|---|---|---|
| How many eggs will be collected in an IVF cycle? | Well — this is what the test is for | AMH is secreted by granulosa cells of pre-antral and small antral follicles, so it is close to a direct count of the recruitable pool. It is used to choose a stimulation protocol and starting dose, and to flag both poor and excessive responders |
| Will I conceive naturally this year? | Poorly | Natural conception depends on egg quality, tubal patency, ovulation, the sperm and coital timing. AMH measures the size of the pool, not the quality of what is in it. Population studies find little or no association between AMH and time to natural conception in women without infertility |
| Am I likely to have a low response to stimulation? | Well, with the antral follicle count | Low AMH with a low antral follicle count identifies poor ovarian response, which is what the Bologna and POSEIDON criteria are built on |
| Am I at risk of ovarian hyperstimulation? | Well | A high AMH predicts an exaggerated response, and the protocol is modified accordingly |
| Do I have polycystic ovary syndrome? | Supportive, not diagnostic | AMH is typically high because there are many small antral follicles. Recent international guidance accepts AMH as an alternative to an antral follicle count for the polycystic ovarian morphology criterion in adults, but not as a stand-alone diagnosis |
| When will I reach the menopause? | Only loosely | AMH correlates with time to menopause across populations, but the prediction interval for an individual woman spans years. It should not be used to plan a life |
| Is the ovary still there, or is there granulosa cell tumour recurrence? | Yes, in those specific settings | AMH is undetectable after bilateral oophorectomy, and is used as a tumour marker in granulosa cell tumours |
Mayo Clinic Laboratories age-specific reference values, Roche Elecsys AMH
| Group | ng/mL | pmol/L |
|---|---|---|
| Female, 15–19 years | 0.62–7.8 | 4.43–55.71 |
| Female, 20–24 years | 1.2–12 | 8.57–85.71 |
| Female, 25–29 years | 0.89–9.9 | 6.36–70.71 |
| Female, 30–34 years | 0.58–8.1 | 4.14–57.86 |
| Female, 35–39 years | 0.15–7.5 | 1.07–53.57 |
| Female, 40–44 years | 0.03–5.5 | 0.21–39.29 |
| Female, 45–50 years | <2.6 | <18.57 |
| Female, 51–55 years | <0.88 | <6.29 |
| Female, over 55 years | <0.03 | <0.21 |
| Male, over 12 years | <13 | <92.86 |
What changes an AMH result without the ovary changing
| Factor | Effect on AMH | What to do about it |
|---|---|---|
| Combined oral contraceptive | Lowered by roughly a quarter — 23.7% lower in COC users in a cross-sectional series of 27,125 women, with similar reductions for the implant and the vaginal ring | A result taken on the pill underestimates ovarian reserve. Where the number will drive a decision, repeat it after stopping — values recover over a few months |
| Change of assay or laboratory | Differences of a third or more between platforms on the same serum | Keep serial results on one method, and record which. A change of assay starts a new series |
| Day of the cycle | Minimal — AMH varies only slightly across the cycle, which is its practical advantage over FSH | No need to time the sample, unlike day 2–5 FSH and oestradiol |
| GnRH agonist treatment, recent ovarian surgery, chemotherapy | Lowered, sometimes transiently and sometimes permanently | Interpret in context; post-chemotherapy recovery can take many months |
| Vitamin D status, BMI, smoking | Small and inconsistent effects in the literature | Not worth correcting for in practice |
| Pregnancy | Modestly lowered | Not a setting in which AMH should be measured |
| Very high biotin intake (some immunoassays) | Can interfere with streptavidin-biotin assay formats | Stop high-dose supplements before testing if the laboratory advises it |
A count of the follicle pool — not a verdict on fertility
Anti-Müllerian hormone is reported in nanograms per millilitre in North America and in picomoles per litre in the UK and much of Europe, and the factor between them is 7.14286: one nanogram per millilitre is 7.14 pmol/L, so 2.0 ng/mL is 14.29 pmol/L and a report of 14.3 pmol/L is the same result as one of 2.0 ng/mL. Micrograms per litre are identical to nanograms per millilitre. The molar figure is a convention rather than a strict measurement — AMH is a 140 kDa dimeric glycoprotein circulating as a mixture of precursor and cleaved fragments — but 7.14 is the factor every laboratory and every published nomogram uses, so it is the one to use.
AMH is secreted by the granulosa cells of pre-antral and small antral follicles, which makes it close to a blood test for the size of the remaining follicle pool. That is precisely what it is good for. It predicts how many oocytes will be retrieved in an IVF cycle well enough to choose a stimulation protocol and a starting dose, it identifies women likely to respond poorly, and it flags those at risk of an exaggerated response and ovarian hyperstimulation syndrome. What it does not do is predict whether a woman will conceive naturally. Natural conception depends on egg quality, on ovulation, on tubal patency, on the sperm and on timing; AMH measures how many follicles remain, not what is inside them, and studies in women without known infertility find little relationship between AMH and time to pregnancy. A low AMH is a reason to have a conversation about ovarian reserve; it is not a statement that someone cannot have a baby, and women with low AMH conceive spontaneously every day.
Its practical advantage over FSH is that it is stable. FSH has to be measured on days 2 to 5 of the cycle and rises only late, once the follicle pool is already substantially depleted; AMH varies only slightly across the cycle and can be taken on any day, which is why it has largely displaced FSH as the first-line marker of ovarian reserve. It is also high in polycystic ovary syndrome, where the many small antral follicles make a great deal of it, and recent international guidance accepts it in adults as an alternative to an ultrasound antral follicle count for the polycystic ovarian morphology criterion — though not as a diagnosis on its own.
Two things will move an AMH result without anything having changed in the ovary, and both are worth knowing before a number is taken to heart. The combined oral contraceptive lowers AMH by roughly a quarter — 23.7% in a cross-sectional series of 27,125 women, with comparable reductions for the implant and the vaginal ring — so a result measured on the pill underestimates ovarian reserve and should be repeated off it where the value will drive a decision. And the commercial assays are not interchangeable: they are calibrated differently, differences of a third or more between platforms on the same serum have been reported, and a change of laboratory can look exactly like a fall in ovarian reserve. Serial AMH results should stay on one method, in one laboratory, with the method recorded — and any age-specific interval, including the ones on this page, belongs to the assay it was derived on.
Frequently asked questions
How do you convert AMH from ng/mL to pmol/L?
Multiply by 7.14286. So 1 ng/mL is 7.14 pmol/L and 2 ng/mL is 14.29 pmol/L. To go the other way, divide by 7.14286 — a UK report of 21.4 pmol/L is 3.0 ng/mL. Micrograms per litre are identical to nanograms per millilitre. Since North American laboratories report ng/mL and UK and European ones pmol/L, an AMH quoted without its unit is ambiguous by a factor of seven.
Does a low AMH mean I cannot get pregnant?
No. AMH estimates the size of the remaining follicle pool, not the quality of the eggs in it, and those are different things. It predicts the response to ovarian stimulation in IVF well, which is what it was developed for, but it predicts natural conception poorly — studies in women without known infertility find little association between AMH and how long it takes to become pregnant. A low AMH is a reason for a conversation about ovarian reserve and about timing, not a verdict. Women with low AMH conceive naturally.
Does AMH need to be measured on a particular day of the cycle?
No, and that is its main practical advantage over FSH. AMH comes from the pre-antral and small antral follicles rather than from the dominant follicle, so it varies only slightly across the menstrual cycle and can be taken on any day. FSH, by contrast, must be drawn on days 2 to 5 with an oestradiol alongside it to be interpretable, and it only rises once the follicle pool is already well depleted.
Does the contraceptive pill affect AMH?
Yes — it lowers it. In a cross-sectional study of 27,125 individuals, AMH was 23.7% lower in combined oral contraceptive users than in non-users, with similar reductions for the implant and the vaginal ring. So a result measured while on the pill underestimates ovarian reserve, by roughly a quarter on average, and values recover over some months after stopping. If an AMH is going to drive a decision about fertility treatment or egg freezing, it is better repeated off hormonal contraception, and a result taken on it should be interpreted with that in mind.
Why is my new AMH different from my last one?
Before concluding that your ovarian reserve has fallen, check three things: whether the two results were measured on the same assay in the same laboratory, whether either was taken while you were on hormonal contraception, and how wide the reference interval for your age actually is. Commercial AMH assays are calibrated differently and are not interchangeable — differences of a third or more between platforms on the same serum have been reported — so a change of laboratory can imitate a real fall. Serial AMH results are only comparable within one method.
What does a high AMH mean?
Usually that there are a lot of small antral follicles. In a woman with irregular or absent periods and clinical or biochemical androgen excess, that supports polycystic ovary syndrome, and international guidance now accepts AMH in adults as an alternative to an ultrasound antral follicle count for the polycystic ovarian morphology criterion — though not as a diagnosis by itself. In someone about to undergo ovarian stimulation, a high AMH predicts a strong response and a raised risk of ovarian hyperstimulation syndrome, which is a reason to modify the protocol and the starting dose rather than to avoid treatment.
Related calculators
References
- Mayo Clinic Laboratories. Test ID: AMH1 — Antimullerian Hormone, Serum. Roche Elecsys electrochemiluminescence immunoassay. Female reference values: 20–24 years 1.2–12 ng/mL; 25–29 years 0.89–9.9; 30–34 years 0.58–8.1; 35–39 years 0.15–7.5; 40–44 years 0.03–5.5; 45–50 years <2.6 ng/mL.
- Bernardi LA, Weiss MS, Waldo A, et al. Anti-Müllerian hormone levels among contraceptive users: evidence from a cross-sectional cohort of 27,125 individuals. Am J Obstet Gynecol. 2021;225(5):543.e1–543.e9. doi:10.1016/j.ajog.2021.06.050 — combined oral contraceptive users 23.68% lower than non-users.
- Practice Committee of the American Society for Reproductive Medicine. Testing and interpreting measures of ovarian reserve: a committee opinion. Fertil Steril. 2020;114(6):1151–1157. doi:10.1016/j.fertnstert.2020.09.134
- Steiner AZ, Pritchard D, Stanczyk FZ, et al. Association Between Biomarkers of Ovarian Reserve and Infertility Among Older Women of Reproductive Age. JAMA. 2017;318(14):1367–1376. doi:10.1001/jama.2017.14588
- Teede HJ, Tay CT, Laven J, et al. Recommendations from the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome. J Clin Endocrinol Metab. 2023;108(10):2447–2469. doi:10.1210/clinem/dgad463
Medical Disclaimer: The tools and content provided here are for educational and reference purposes only. They are not intended to substitute for professional medical advice, diagnosis, or treatment. Clinical decisions should always be based on the comprehensive assessment of a qualified healthcare professional.