Dynamics of serum anti-Mullerian hormone levels during the luteal phase of controlled ovarian hyperstimulation

BACKGROUND: To investigate the dynamics of serum anti-Mullerian hormone (AMH) levels during the luteal phase of controlled ovarian hyperstimulation (COH) and its possible association with follicle development. METHODS: We prospectively studied 34 women undergoing COH with GnRH agonist and FSH. On the day of hCG (dhCG), serum AMH, estradiol (E-2), progesterone and hCG levels were measured, and ovarian follicles were sorted into three size classes: <12, 12-15 and 16-22 mm. Hormonal measurements were repeated 4 days (hCG+4) and 7 days (hCG+7) after hCG. RESULTS: From dhCG to hCG+4, we observed a decline in serum AMH levels (-64+/-3%; P<0.0001), which paralleled that of E-2 levels. From hCG+4 to hCG+7, an increase in AMH levels occurred (82+/-28%; P<0.02), whose magnitude was correlated with the number of < 12 mm follicles (r=0.68; P<0.0001) but not with other follicle size classes nor with the remaining hormone levels. CONCLUSIONS: After hCG, AMH levels initially decline, presumably as an effect of follicle luteinization, then increase during the mid-luteal phase. Although the mechanisms implicated in the mid-luteal AMH increase are unclear, its positive association with small follicle count, but not with luteal progesterone and E-2 levels, supports the hypothesis that AMH levels might reflect luteal follicle development.