AMH and polycystic ovary syndrome: Regarding PCOS patients with a BMI<24 kg/m2, compared with the PTB rate of the AMH <2.71 ng/ml group, those of the different groups were not significantly different (AMH 2.71-4.08, AOR (95% CI)=1.01 (0.52-2.00), P=0.99; AMH 4.09-6.45, AOR (95% CI)=0.93 (0.45-1.91), P=0.85; AMH>6.45, AOR (95% CI)=0.78 (0.35-1.73), P=0.54).