In areas of stable transmission, pregnant women, especially during the first and second pregnancies, have an increased susceptibility to Plasmodium falciparum malaria, malaria-related anaemia and an increased risk of having low birthweight babies. Intermittent Preventive Treatment in pregnancy(IPTp) with sulphadoxine-pyrimethamine has been shown to be effective in reducing the effects of malaria in pregnancy. This has mainly been in areas of perennial transmission and there is a need to study this effect in intense seasonal transmission settings. The emergence and spread of resistance to SP is likely to undermine its useful lifespan and it is important that other antimalarials that are safe and effective are identified for use in IPTp. The options are however limited. Amodiaquine has been shown to be effective in treatment of clinical cases of malaria, even in areas where chloroquine resistance is prevalent, and its combination with SP has been associated with favourable results. Both are affordable. However, there is limited data on their use in pregnancy. This study aims to assess the efficacy of SP in an area of intense seasonal transmission, and evaluate the safety and efficacy of amodiaquine and a combination of sulphadoxine-pyrimethamine and amodiaquine as possible alternatives to SP for use as IPTp.