Pregnant women greater than or equal to 20 weeks gestation with P. falciparum parasitemia on peripheral blood film will be given an insecticide-treated net (ITN) and will receive CD (1.5 or 2 tablets daily for 3 days, depending on weight). All study drug dosing will be observed. Women will be examined, adverse events recorded, and blood samples collected at days 0, 1, 2, 3, 7, 14, 21, and 28 after treatment, and thereafter every 14 days until delivery. Women will be further randomized to receive additional blood draws for pharmacokinetic analyses using a modified rich PK schedule. Each woman will only have 2 additional blood draws. Women at delivery will have peripheral and placental blood films prepared. Newborns will be weighed, examined, and gestational age determined. Women requiring antimalarial treatment for parasitemia at any point between enrollment and delivery will be treated with quinine. Adverse effects will be assessed at each scheduled visit, any sick visits during the study, and at delivery.