Background: Data on variations in anti-Müllerian hormone (AMH) levels according to ovarian reserve are scant. The aim of this study was to investigate changes in AMH levels during controlled ovarian hyperstimulation with a GnRH-antagonist protocol for in vitro fertilization (IVF).
Methods: Prospective, observational study of 46 women. The subjects were divided into three cohorts according to ovarian reserve levels: polycystic ovary syndrome (PCOS; N.=19), low ovarian reserve (LOR; N.=11), and normoreserve (NR; N.=16). Serum AMH concentration was measured at baseline (cycle day 2-3 before follicle stimulating hormone [FSH] administration) and just prior to GnRH-antagonist and human chorionic gonadotropin (hCG) administration. AMH concentration in follicular fluid (FF) was assessed on the day of oocyte retrieval.
Results: AMH serum concentration decreased significantly (P<0.001) and progressively in all three groups from baseline (initiation of stimulation) to all subsequent assessments. Serum AMH levels were significantly higher in the PCOS group at all determinations: (AMH1: 8.18±6.26ng/mL, AMH2: 5.3±3.97ng/mL, AMH3: 2.19±1.31ng/mL) versus the NR group (AMH1: 2.94±1.53ng/mL, AMH2: 1.44±0.77ng/mL, AMH3: 0.71±0.57ng/mL) and LOR group (AMH1: 0.63±0.42ng/mL, AMH2: 0.58±0.4ng/mL, AMH3: 0.31±0.2ng/mL). No significant between-group differences were observed for AMH levels in FF (PCOS: 3.56±3.19ng/mL, NR: 4.06±5.44ng/mL, LOR: 1.31±0.47ng/mL) nor for fertilization rate, number of top quality embryos, or clinical pregnancy rates.
Conclusions: Serum AMH levels gradually decrease during GnRH-antagonist protocol for IVF. This decrease starts at the beginning of the follicular phase and continues up to the day of hCG administration. These results underscore the important role that AMH plays in the process of folliculogenesis and dominant follicle selection.