Comparison of 3 Different AMH Assays With AMH Levels and Follicle Count in Women With Polycystic Ovary Syndrome

CONTEXT: Anti-Müllerian hormone (AMH) levels strongly correlate with the number of antral follicles (total follicle count, TFC) in the ovary. In women with polycystic ovary syndrome (PCOS), this is reflected by significantly increased serum AMH levels. Different assays have been developed to measure AMH. However, little is known about the interassay correlation in women with increased AMH levels. OBJECTIVE: To investigate the correlation of AMH values between different AMH assays and with TFC in PCOS patients. METHODS: AMH levels were measured in 1660 PCOS patients, using 3 different AMH assays: Gen II (Beckman Coulter); picoAMH (Ansh Labs); and Elecsys (Roche). Passing Bablok regression was used to compare assay methods. Spearman's correlation was used to correlate AMH levels and TFC. RESULTS: Strong interassay correlations were present over the total range of AMH levels (0.81-0.94). Stratification in subgroups, revealed an AMH level-dependent interassay correlation with strong interassay correlations in the low (<2.80 ng/mL) and high (>7.04 ng/mL) subgroups (0.62-0.86). However, the correlation in the mid-AMH subgroup (2.80-7.04 ng/mL) was only moderate (0.28-0.56). A strong correlation was present between the total range of AMH levels and TFC (0.57-0.62). However, in all 3 AMH subgroups the correlation became moderate at best, independently of assay method (0.11-0.45). CONCLUSION: In conclusion, both the interassay correlation and the correlation between AMH level and follicle count depend on the range of serum AMH levels. This once more emphasizes the need of a standardization of AMH measurement for an accurate interpretation of AMH in clinical practice.