Anti-Müllerian hormone and inhibin B variability during normal menstrual cycles.

OBJECTIVE

To describe anti-Müllerian hormone (AMH) variation across normal menstrual cycles.

DESIGN

Cohort study.

SETTING

Academic environment.

PATIENT(S): Twenty regularly menstruating women.

INTERVENTION(S): Serum AMH and inhibin B assayed daily during one normal menstrual cycle.

MAIN OUTCOME MEASURE(S): Intracycle variability of AMH and inhibin B.

RESULT(S): Data were classified into quartiles of AMH area-under-the-curve (AUCs). Mean AMH AUC was 15.7 ng/mL for quartile 1 versus 43.5, 80.9 and 144.9 ng/mL for quartiles 2, 3, and 4. Mean AMH levels (ng/mL) were 0.67, 1.71, 3.02, and 5.33, respectively. There was no variation in quartile 1 AMH rate of change from stochastic modeling, but in quartiles 2 to 4, there were increased rates of change in days 2 to 7. Women in quartile 1 had the lowest mean inhibin B (24.2 pg/mL vs. 44.3, 43.2, and 42.2 pg/mL), and had shorter menstrual cycles (24.6 days) than women in quartiles 3 and 4 (28.2 and 28.4 days).

CONCLUSION(S): There were two menstrual cycle patterns of AMH. The "aging ovary" pattern included low AMH levels with little variation, lower inhibin B, and shorter cycle lengths. The "younger ovary" pattern included higher AMH levels with significant variation days 2 to 7, suggesting that for women with AMH>1 ng/mL, the interpretation of AMH levels is contingent upon the day of the menstrual cycle on which the specimen is obtained.