Malaria preventive strategies in pregnancy were assessed in a health center randomized trial comparing intermittent preventive treatment with sulfadoxine-pyrimethamine (IPTp-SP) with and without community based promotional activities in rural Burkina Faso. The study involved 2,240 secundigravidae and secundigravidae and evaluated factors associated with antenatal clinic (ANC) attendance and uptake of IPTp-SP. With promotion, 64.2% completed > or = 3 ANC visits compared with 44.7% without (P = 0.05). Complete uptake of IPTp-SP was 71.8% with and 49.1% without promotion (P = 0.008). The IPTp-SP uptake was lowest in adolescents delivering during high malaria transmission with (29%) or without promotion (30%). Uptake of SP was higher during the low transmission season than in the high transmission season (adjusted odds ratio = 2.17, 95% confidence interval = 1.59-3.03). Community sensitization increased ANC attendance and IPTp-SP uptake. Adolescents were the most difficult to reach, particularly during the high malaria transmission period. The impact of IPTp-SP will be limited unless this high risk group is protected.