The mean Hb concentration was 10.6 g/dL at baseline and 262/408 (64.2%) women were diagnosed with anaemia (Hb<11 g/dL) in pregnancy, 48/146 (32.9%) subsequently developed anaemia intrapartum or postpartum and 89/310 (28.7%) of all cases of anaemia remained unresolved by 2 weeks postdelivery. This evidence concerns the gene GSTM1 and anemia.