Intermittent preventive treatment during pregnancy with sulphadoxine-pyrimethamine may promote Plasmodium falciparum gametocytogenesis.

OBJECTIVES To determine the incidence of gametocytes and the propensity of sulphadoxine-pyrimethamine to promote gametocytogenesis when used as intermittent preventive treatment in pregnancy. SUBJECTS AND METHODS This observational non-interventional study assessed the influence of intermittent preventive treatment with sulphadoxine-pyrimethamine on Plasmodium falciparum gametocytaemia among Nigerian pregnant women. A total of 306 pregnant women were enrolled in the study. RESULTS The 306 pregnant women had 711 events, of which 31 pure gametocytaemic episodes were documented and 27 were recorded among the intermittent preventive treatment users. Only 4 episodes of pure gametocytaemia were recorded in pregnant women who did not receive any dose of sulphadoxine-pyrimethamine (27/129 vs. 4/276, χ(2) = 15.9, p = 0.00006). CONCLUSION Our findings show that intermittent preventive treatment in pregnancy with sulphadoxine-pyrimethamine may predispose to gametocyte carriage in pregnant women resident in the hyperendemic malaria region of southwest Nigeria. We therefore suggest that the use of insecticide-treated nets be encouraged among pregnant women resident in malaria-endemic sub-Saharan Africa in order to reduce malaria transmission.