Change of AMH levels during follicular phase in PCOS patients

Purpose: In healthy women, AMH does not seem to fluctuate significantly during the menstrual cycle. In patients with polycystic ovarian syndrome, however, little is known about cycle fluctuations of AMH levels during monofollicular development. In this study, we examined AMH levels during the follicular phase in PCOS patients receiving antiestrogens or recombinant FSH. Methods: 40 PCOS patients and 33 controls were enrolled in this study prospectively and PCOS patients received either antiestrogens or recombinant FSH for monoovulation induction. AMH levels were determined in the early follicular phase as well as in the preovulatory phase, once the dominant follicle reached a size of at least 18 mm. Wilcoxon signed rank test was used to analyze differences between the early follicular phase and the preovulatory phase. Results: AMH levels do not change during follicular development in controls as well as in PCOS patients with AMH levels < 5 ng/ml, irrespective of antiestrogen or FSH therapy. In PCOS patients with AMH levels ≥5 ng/ml, however, AMH declines significantly during follicular development (p = 0.01). Conclusions: Determination of AMH levels should be done in the early follicular phase in PCOS patients without the influence of antiestrogens or exogenous FSH, because these interventions may lower AMH values in patients with high levels.