GSTM1 and anemia (phenotype): Forty-six percent of mothers had anaemia (Hb < 110 g/L) at booking [LI: 64% vs. NI: 28%, P = 0.01] which increased to 62% by 20 wk [LI: 72% vs. NI: 52%, P = 0.1] and to 64% by 30 wk [LI: 80% vs. NI: 46%, P = 0.01] (See Table 3).