AMH and COVID-19: Both basal level and all COVID-19 women had significant lower serum AMH level (0.19/0.28 vs. 1.12 ng/ml, P = 0.003/0.027), and lower serum AMH ratio (AMH ≤ 1.1 ng/ml: 75.00/70.40 vs. 49.70%, P = 0.009/0.004) (Figures 2C,D, Supplementary Table 2).