Unit Converter
anti‐Mullerian hormone (AMH)
(Müllerian-Inhibiting Substance – Ovarian Reserve Biomarker)
Synonyms
- Anti-Müllerian Hormone
- AMH
- Müllerian-Inhibiting Substance (MIS)
- Müllerian-Inhibiting Factor (MIF)
- Ovarian reserve hormone
- Sertoli-cell hormone (in males)
Units of Measurement
pmol/L, ng/mL, ng/dL, ng/100mL, ng%, ng/L, pg/mL
(Modern labs commonly use ng/mL or pmol/L; conversion is required.)
Description
AMH is a glycoprotein hormone belonging to the TGF-β family.
It is produced by:
- Females: granulosa cells of pre-antral and small antral follicles
- Males: Sertoli cells (high during fetal life; falls after puberty)
AMH is the most stable marker of ovarian reserve because it reflects the size of the developing follicle pool.
Uses:
- Infertility evaluation
- Predicting ovarian response to IVF
- Diagnosing PCOS
- Differentiating ovarian masses
- Assessing puberty disorders
- Monitoring granulosa-cell tumors
Physiological Role
In Females
- Reflects population of small growing follicles
- Declines with age; lowest at menopause
- Not cycle-dependent (unlike FSH, LH, estradiol)
In Males
- Causes regression of Müllerian ducts in fetal development
- Marker for Sertoli cell function
- Elevated in persistent Müllerian duct syndrome (PMDS)
Clinical Significance
Elevated AMH
1. Polycystic Ovary Syndrome (PCOS)
- Markedly elevated AMH due to increased follicle count
- AMH > 5–7 ng/mL (>35–50 pmol/L) supports PCOS diagnosis
2. Granulosa Cell Tumors
High AMH indicates tumor activity; used for:
- Diagnosis
- Treatment monitoring
- Recurrence detection
3. Ovarian Hyperstimulation Syndrome (OHSS) Risk
Higher AMH → excessive ovarian response during IVF.
Low AMH
1. Diminished Ovarian Reserve (DOR)
Seen in:
- Aging (>35 years)
- Premature ovarian insufficiency (POI)
- Chemotherapy/radiation
- Smoking
- Severe endometriosis
- Ovarian surgery (e.g., cystectomy)
2. After IVF Ovarian Stimulation
Follicle depletion temporarily lowers AMH.
3. Obesity
Moderately lowers AMH.
Reference Intervals
Adult Females (Reproductive Age)
| AMH Level | ng/mL | pmol/L | Interpretation |
| Very low | < 0.3 | < 2.1 | Poor reserve |
| Low | 0.3–1.0 | 2.1–7.1 | Reduced reserve |
| Normal | 1.0–4.0 | 7.1–28 | Normal reserve |
| High | > 4.0 | > 28 | PCOS / High response |
| Very high | > 7.0 | > 50 | Strongly suggests PCOS |
Men
- High in infancy → falls to low levels in adulthood
(AMH is not routinely used for adult male evaluation)
Children
- Elevated in boys (Sertoli function)
- Low in girls until puberty
Age-Related AMH Trends in Women
| Age | Typical AMH |
| 20–25 yrs | 3–5 ng/mL |
| 30 yrs | 2–3 ng/mL |
| 35 yrs | 1.0–1.5 ng/mL |
| 40 yrs | 0.5–1.0 ng/mL |
| 45 yrs | <0.5 ng/mL |
Unit Meanings
| Unit | Explanation |
| pmol/L | picomole per liter |
| ng/mL | nanogram per milliliter |
| ng/dL | nanogram per deciliter |
| ng/100mL | ng% (identical to ng/dL) |
| ng% | nanogram per 100 mL |
| ng/L | nanogram per liter |
| pg/mL | picogram per milliliter |
Diagnostic Uses
1. Ovarian Reserve Testing
- Determines fertility potential
- Useful in IVF counseling
- Predicts ovarian response to stimulation
2. PCOS Diagnosis
AMH is significantly elevated due to follicular excess.
3. Granulosa-Cell Tumor Marker
Most sensitive biochemical marker.
4. Puberty Disorders
- Delayed puberty
- Hypogonadism
- Persistent Müllerian duct syndrome (in males)
5. Predicting Menopause
Low AMH predicts earlier menopause, but not for exact timing.
Analytical Notes
- Measured using automated immunoassays (e.g., Roche Elecsys).
- Not significantly affected by menstrual cycle phase.
- Avoid biotin supplements for 48 hours (assay interference).
- Hemolysis has minimal effect.
- Different assays historically gave different values — standardization has improved recently.
Clinical Pearls
- AMH is more stable and cycle-independent compared to FSH and estradiol.
- Low AMH does not mean infertility; it reflects quantity, not egg quality.
- High AMH + high AFC → high OHSS risk.
- AMH is a strong biomarker for PCOS, sometimes more sensitive than AFC.
- AMH declines years before FSH begins to rise.
Interesting Fact
AMH was originally discovered as the hormone responsible for male fetal sexual differentiation, long before it became one of the most powerful markers for ovarian reserve and fertility assessment.
References
- Tietz Clinical Chemistry and Molecular Diagnostics, 8th Edition - Reproductive Hormones.
- ASRM/ESHRE Guidelines - Ovarian Reserve Testing & AMH.
- Mayo Clinic Laboratories - AMH Test Catalog.
- ARUP Consult - Fertility Hormone Interpretation.
- IFCC - Hormone Standardization Guidelines.
- NIH / MedlinePlus - AMH Overview.
- Fertility & Sterility / Human Reproduction - AMH Clinical Applications.