The study determined the prevalence of malaria parasitemia among pregnant women using Sulphadoxine-pyrimethamine (SP) for intermittent preventive treatment (IPT) and assessed Plasmodium falciparum dihydropteroate reductase (Pfdhfr) and dihydropteroate synthetase (Pfdhps) resistance genes among the subjects. Three hundred and ninety consenting pregnant women attending antenatal clinics in Nnewi, Anambra State, Nigeria were recruited. Of this, 336 of the women were using SP for IPT, while fifty-four of the women were non-users of SP. Polymerase Chain Reaction was used in the characterization of Plasmodium species while the Sanger sequencing method was used in sequencing assay. Of the 336 pregnant women SP users, 73 (21.7%) and, 41 (12.2%) of the neonates had malaria parasitemia while 29 (53.7%) of the 54 non-users of SP and 14 (25.4%) of the babies had malaria parasitemia (p=0.022). Plasmodium falciparum and Plasmodium vivax parasitemia among subjects on IPTp-SP was 38 (11.3%) and 30 (8.9%) respectively. The prevalence of Pfdhfr and Pfdhps resistance genes in pregnant women was 11 (3.3%) and 10 (2.9%) respectively. Malaria parasitemia was significantly higher among non-users of SP. The presence of P. falciparum resistance genes among IPTp-SP users could lead to treatment failures. Therefore, novel drugs should be sought to replace SP. Key words: Plasmodium, Sulphadoxine-pyrimethamine, pregnancy, polymerase chain reaction (PCR), Resistant gene, Nigeria.
