Malaria chemoprophylaxis, infection of the placenta and birth weight in Gambian primigravidae.

A randomized, double blind, placebo-controlled community based trial of Maloprim (pyrimethamine 12.5 mg+dapsone 100 mg) administered to primigravid pregnant women by Traditional Birth Attendants was carried out in a rural area of The Gambia, West Africa. Placental histology showed less malaria infection in women who received chemoprophylaxis than in those who received placebo. The birth weight of children born to women who received chemoprophylaxis was increased by an average of 153 g. Within the treatment groups, there were no significant differences in the birthweights of babies born to women who had histological evidence of malaria infection of the placenta compared to those who had no malaria infection. This study confirms the beneficial effect of malaria prophylaxis for primigravid pregnant women but questions the mechanism by which malaria affects foetal development.