GSTM1 and anemia (phenotype): The results showed that LBW risk, compared with non-anemia, increased significantly in the presence of moderate anemia (Hb < 95 g/L) (adjusted OR: 6.5, 95%CI: 1.6, 26.7) but not mild anemia (95 ≤ Hb < 120 g/L) (adjusted OR: 2.0, 95%CI: 0.7, 5.9).