Anti-Müllerian Hormone
AMH· also: Anti-Müllerian Hormone
Clinical Overview
AMH (Anti-Müllerian hormone) is secreted by granulosa cells of preantral and small antral follicles in the ovary. It directly reflects the size of the ovarian follicle pool and is the best serum marker of ovarian reserve. AMH levels decline progressively with age and reach undetectable levels after menopause. In men, AMH is produced by Sertoli cells in the testes and is used in pediatric endocrinology.
Why This Test Matters
AMH is the most reliable test for ovarian reserve assessment for fertility counseling and IVF planning. A low AMH predicts poor response to ovarian stimulation (fewer eggs retrieved) in IVF, while a very high AMH (often in PCOS) predicts an excessive response and OHSS risk. Unlike FSH, AMH can be measured on any day of the menstrual cycle, shows less inter-cycle variability, and provides earlier warning of declining reserve. AMH does not predict natural pregnancy potential — women with low AMH can still conceive naturally.
Reference RangesWHO/IFCC standards
| Age Group | Sex | Reference Range | Unit | Notes |
|---|---|---|---|---|
| Adults (18–64) | Female | 1 – 3.5 | ng/mL | Good reserve (typical age 25–35) |
| Adults (18–64) | Female | 0.3 – 0.9 | ng/mL | Low reserve |
Also reported in: pmol/L.
What Causes Abnormal Results?
High AMH Causes
- Polycystic ovary syndrome (PCOS — AMH is often 2–4× normal)
- Young age (AMH peaks around age 25)
- Multiple antral follicles for any reason
Low AMH Causes
- Advanced reproductive age (AMH declines with age)
- Premature ovarian insufficiency (POI)
- Chemotherapy or radiation to the pelvis
- Ovarian surgery (especially for endometriomas)
- Severe endometriosis
- Turner syndrome
- Genetic mutations (FMR1 premutations)
Signs & Symptoms to Watch For
How to Prepare for This Test
AMH can be measured on any day of the menstrual cycle — no specific timing is needed. No fasting required. Note that hormonal contraceptives (oral pills, implants, injections) suppress AMH and may give falsely low results — a 3-month washout period may be needed for accurate assessment.
Factors That Can Affect Results
- Oral contraceptives and hormonal IUDs (significantly suppress AMH)
- Vitamin D deficiency (associated with lower AMH)
- Recent ovarian surgery (acutely lowers AMH)
- Assay brand differences (AMH Gen II vs. Elecsys — different reference ranges)
Related Topics
Frequently Asked Questions
Can a low AMH prevent natural pregnancy?
No. AMH reflects the quantity of eggs remaining, not egg quality, and it does not measure the chance of a natural pregnancy. Women with low AMH conceive naturally every day — AMH is primarily a predictor of IVF response, not of natural fertility. However, a very low AMH may signal that the "fertile window" before menopause is shorter, which is important for family planning.
What AMH level is needed to proceed with IVF?
There is no minimum AMH required to attempt IVF, but AMH helps set expectations for the number of eggs likely to be retrieved. An AMH below 0.5–1.0 ng/mL typically predicts a poor response (fewer than 3–4 eggs retrieved), which lowers IVF success rates but does not make IVF impossible. Clinics use AMH to individualize stimulation protocols and counsel couples about realistic success rates.