GSTM1 and hydrops fetalis: No difference was detected in Hb (116.6 ± 2.8 g/L, n = 19 in the NA-HF group, and 117.2 ± 2.5 g/L, n = 44 in the A-LF group) and sFer (39.3 ± 15.0 μg/L, n = 19 in the NA-HF group, and 30.8 ± 3.6 μg/L, n = 44 in the A-LF group) between the two groups (Table 2).