Efficacy of malaria prevention during pregnancy in an area of low and unstable transmission: an individually-randomised placebo-controlled trial using intermittent preventive treatment and insecticide-treated nets in the Kabale Highlands, southwestern Uganda.

Intermittent preventive treatment of malaria during pregnancy (IPTp) and insecticide-treated nets (ITN) are recommended malaria interventions during pregnancy; however, there is limited information on their efficacy in areas of low malaria transmission in sub-Saharan Africa. An individually-randomised placebo-controlled trial involving 5775 women of all parities examined the effect of IPTp, ITNs alone, or ITNs used in combination with IPTp on maternal anaemia and low birth weight (LBW) in a highland area of southwestern Uganda. The overall prevalence of malaria infection, maternal anaemia and LBW was 15.0%, 14.7% and 6.5%, respectively. Maternal and fetal outcomes were generally remarkably similar across all intervention groups (P>0.05 for all outcomes examined). A marginal difference in maternal haemoglobin was observed in the dual intervention group (12.57g/dl) compared with the IPTp and ITN alone groups (12.40g/dl and 12.44g/dl, respectively; P=0.04), but this was too slight to be of clinical importance. In conclusion, none of the preventive strategies was found to be superior to the others, and no substantial additional benefit to providing both IPTp and ITNs during routine antenatal services was observed. With ITNs offering a number of advantages over IPTp, yet showing comparable efficacy, we discuss why ITNs could be an appropriate preventive strategy for malaria control during pregnancy in areas of low and unstable transmission.