In patients who underwent IVF/ICSI due to polycystic ovary syndrome (PCOS), we found a significant decrease in AMH serum levels between the first [AMH 9.7 ng/mL (IQR 7.4–14.4)] and the third [AMH 5.3 ng/mL (IQR 3.3–10.4)] IVF/ICSI cycles (p = 0.026). The gene discussed is AMH; the disease is polycystic ovary syndrome.