Abstract
BACKGROUND: AMH is widely used for assessing ovarian reserve, and it is particularly convenient, because it is thought to have minimal variability throughout the menstrual cycle. However, studies assessing the stability of AMH over the menstrual cycle have been conflicting. PURPOSE: The purpose of this study is to determine whether AMH levels vary across the normal menstrual cycle. DESIGN: A multi-center, prospective cohort study conducted at three US centers. METHODS: Fifty females with regular menstrual cycles aged 18-45 underwent serial venipuncture every 3-5 days starting in the early follicular phase and lasting up to 10 collections. AMH was tested using the Access 2 immunoassay system. RESULTS: Age-adjusted mixed-effect models utilizing data from 384 samples from 50 subjects demonstrated a within subject standard deviation of 0.81 (95% CI 0.75-0.88) with a coefficient of variation of 23.8% across the menstrual cycle and between subject standard deviation of 2.56 (95% CI 2.13-3.21) with a coefficient of variation of 75.1%. Intra-class correlation (ICC) of AMH across the menstrual cycle was 0.91. CONCLUSION: Overall, AMH levels, using the automated Access AMH assay, appear to be relatively stable across the menstrual cycle. Fluctuations, if any, appear to be small, and therefore, clinicians may advise patients to have AMH levels drawn at any time in the cycle.