GSTM1 and malaria: Although, the absence of peripheral blood malaria parasites might reflect low rates of transmission of malaria in the study area (as indicated by relatively high Hb levels) or wide spread use of antimalarials as a result of the improved education on malaria during pregnancy in Ghana, in general, it is plausible that many women may have had submicroscopic peripheral blood parasites undetected by microscopy but detectable by the more sensitive PCR method [16, 17].