GSTM1 and anemia (phenotype): We examined associations between maternal preconception Hb concentrations and anemia with 1) birth outcomes (weight, length, preterm, gestational age, small for gestational age); 2) child Hb at 3 mo, 6 mo, 12 mo, and 24 mo; and 3) motor and mental development at 12 mo and 24 mo (Bayley scales for infant development) and cognitive functioning at 6–7 y (Wechsler Intelligence Scale for Children).