Anti-Müllerian Hormone Levels in Polycystic Ovary Syndrome
Yes, AMH levels are significantly higher in women with PCOS compared with normal ovulatory women. 1 This elevation is a consistent finding that has important diagnostic and pathophysiological implications.
Why AMH is Elevated in PCOS
AMH is elevated in PCOS due to two primary mechanisms:
Increased follicle number: Women with PCOS have an increased number of pre-antral and small antral follicles, which are the primary source of AMH production 1, 2
Higher production per follicle: Each follicular unit in PCOS produces more AMH than in women without PCOS 2
The elevation is substantial, with AMH levels typically being:
- Two to four-fold higher in PCOS patients compared to controls 3
- In one study, women with PCOS had median AMH levels of 10.82 ng/ml compared to 4.03 ng/ml in controls 4
Pathophysiological Role of AMH in PCOS
AMH appears to play an important role in the pathophysiology of PCOS:
- It inhibits the recruitment of primordial follicles out of the resting oocyte pool 1
- It suppresses follicle-stimulating hormone (FSH) action, contributing to ovulatory disturbances 1
- Animal models suggest AMH may have a possible causal role in the development of PCOS through in-utero exposure of the fetus to high AMH levels 1
Diagnostic Value of AMH in PCOS
AMH has been proposed as a valuable diagnostic marker for PCOS:
It has high diagnostic accuracy as an isolated marker for PCOS 5
When using 3.34 ng/ml as a cut-off point, AMH demonstrates:
- 98% sensitivity
- 93% specificity
- 93% positive predictive value
- 98% negative predictive value 3
AMH could potentially replace ultrasound for detecting polycystic ovarian morphology (PCOM) 1, 5
Clinical Applications and Considerations
AMH measurement offers several clinical advantages:
- It could replace more costly and less accessible ultrasound in PCOS diagnosis 1
- It's particularly valuable when transvaginal ultrasound is unacceptable to patients or unavailable 1
- AMH levels can predict response to treatments such as laparoscopic ovarian drilling (LOD) 6
Important Caveats
Several challenges exist in using AMH for PCOS diagnosis:
- Assay standardization issues: Different AMH assays may yield varying results 1
- Genetic variants: Some women with PCOS may have AMH gene variants that affect AMH measurement while still expressing the PCOS phenotype 4
- Age variation: AMH levels change across the lifespan, requiring age-specific reference ranges 1
- International consensus needed: Despite its promise, AMH has not yet been incorporated into routine diagnostic criteria 2
Conclusion
AMH is significantly elevated in PCOS and correlates strongly with the syndrome's key features: polycystic ovarian morphology, hyperandrogenism, and oligo/anovulation. This elevation reflects both increased follicle numbers and increased production per follicle, making AMH a promising biomarker for PCOS diagnosis.