The Effect of Intermittent Preventive Treatment of Malaria During Pregnancy and Placental Malaria on Infant Risk of Malaria

[[[ Background: ]]] Intermittent preventive treatment of malaria during pregnancy (IPTp) with dihydroartemisinin-piperaquine (DP) provides greater protection from placental malaria than sulfadoxine-pyrimethamine (SP). Some studies suggest placental malaria alters risk of malaria infection in infants, but few have quantified the effect of IPTp on infant susceptibility to malaria. [[[ Methods: ]]] Infants born to women enrolled in a randomized clinical trial comparing IPTp-SP and IPTp-DP in Malawi were followed from birth to 24 months to assess effect of IPTp and placental malaria on time to first malaria episode and Plasmodium falciparum incidence. [[[ Results: ]]] In total, 192 infants born to mothers randomized to IPTp-SP and 195 randomized to IPTp-DP were enrolled. Infants in IPTp exposure groups did not differ significantly regarding incidence of clinical malaria (incidence rate ratio [IRR], 1.03; 95% confidence interval [CI], .58-1.86) or incidence of infection (IRR, 1.18; 95% CI, .92-1.55). Placental malaria exposure was not associated with incidence of clinical malaria (IRR, 1.03; 95% CI, .66-1.59) or infection (IRR, 1.15; 95% CI, .88-1.50). Infant sex, season of birth, and maternal gravidity did not confound results. [[[ Conclusions: ]]] We did not find evidence that IPTp regimen or placental malaria exposure influenced risk of malaria during infancy in this population. Clinical Trials Registration. NCT03009526 .