Ampath Chat 28.1 – Anti-Müllerian Hormone (AMH) Physiology and Clinical Utility
Authors: Dr Devina Govender & Dr Marita du Plessis
Published: August 2025
🌐 ampath.co.za
What is AMH?
Anti-Müllerian hormone (AMH) is a 140 kDa dimeric glycoprotein belonging to the transforming growth factor beta (TGF-β) superfamily.
- In male embryos, AMH is secreted by Sertoli cells in the testes and causes regression of Müllerian ducts. Without AMH, these ducts develop into female reproductive organs.
- In females, AMH is secreted by granulosa cells of primary and pre-antral ovarian follicles. It serves as a marker of ovarian follicular reserve and becomes undetectable after menopause.
AMH and Polycystic Ovarian Syndrome (PCOS)
PCOS is the most common endocrine disorder in women, affecting 10–13% of reproductive-aged women globally. It has reproductive, metabolic, and psychological consequences.
PCOS increases the risk of:
- Infertility (±50%)
- Type 2 diabetes or pre-diabetes by age 40 (±50%)
- Cardiovascular disease
- Sleep disorders
- High-risk pregnancy
- Premenopausal endometrial cancer
Diagnosis is challenging due to symptom variability and overlap with other conditions. Up to 70% of women remain undiagnosed.
Diagnostic Criteria for PCOS
PCOS is diagnosed using the 2003 Rotterdam criteria, requiring two of the following:
- Clinical or biochemical hyperandrogenism
- Ovulatory dysfunction (e.g., anovulation)
- Polycystic ovaries on ultrasound — or alternatively, AMH levels may now be used instead of ultrasound.
In adolescents, only criteria 1 and 2 are recommended.
Polycystic ovarian morphology (PCOM) is typically assessed via transvaginal ultrasound (TVUS), defined as:
- Antral follicular count (AFC) >20 per ovary
- Ovary volume ≥10ml
Replacing TVUS with a blood test like AMH offers a low-cost, accessible alternative without increasing overdiagnosis.
AMH Cutoff for PCOM Diagnosis
AMH levels correlate with the number of ovarian follicles (2–9 mm) and primordial follicle count. A study by De Loos et al found:
- AMH cutoff: 3.2 ng/mL (23 pmol/L)
- Platform: Roche AMH Plus immunoassay
- Sensitivity: 88.6%
- Specificity: 84.6%
- Applicable age group: Women aged 25–45 years
Ampath now offers this assay.
Sample type: Serum (SST)
AMH in IVF Treatment
AMH reflects ovarian reserve and predicts egg retrieval success in IVF better than age, FSH, inhibin B, or oestradiol.
- Higher AMH = more retrievable oocytes
- AMH levels are stable throughout the menstrual cycle
- Can be measured on any day
AMH is a reliable marker for predicting response to ovarian stimulation and aids in counselling and treatment planning.
Elevated AMH levels can also identify women at risk of ovarian hyperstimulation syndrome. Dosing of recombinant FSH is individualized based on AMH level and patient weight.
AMH in Paediatric Evaluation
AMH testing helps assess testicular function in infants with:
- Disorders of sexual development or ambiguous genitalia
- Cryptorchidism (testes present but not palpable) vs. anorchidism (absent testes)
AMH as a Tumour Marker
AMH levels may be elevated in 76–93% of patients with granulosa cell tumours of the ovaries, which account for ~10% of ovarian tumours.
- AMH combined with CA125 is useful for monitoring treatment response and detecting recurrence.