To explore whether the severity of gestational anemia impacts maternal psychological distress, we performed an analysis comparing the outcomes of women with at least one prenatal Hb < 10.0 g/dL (n = 39) and women with Hb ≥ 10.0 g/dL (n = 1182) at all three measurement points. This evidence concerns the gene GSTM1 and anemia (phenotype).