The lower Hb conc of women in second trimester than those in third trimester was at variance with an earlier report of WHO in which anaemia prevalence was significantly higher in 3rd trimester of pregnancy than in first two trimesters.25 However, the results of this study confirmed another report26 and was attributed to the fact that haemodilution is at its peak in second trimester. This evidence concerns the gene GSTM1 and anemia.