Placental malaria and foetoplacental function: low plasma oestradiols associated with malarial pigmentation of the placenta

Placental biopsies were taken immediately post partum from 65 Gambian mothers who had not received anti-malaria chemoprophylaxis during pregnancy whilst living in an area hyperendemic for Plasmodium falciparum malaria. The biopsies were examined without knowledge of the mothers' health or the outcome of pregnancies. Histologically, they were divided into two groups: those with macrophages containing malarial pigment in the inter-villous spaces, and those without such pathology. Babies with pigmented placentae had a mean (SD) weight for gestational age of 83.3 (10.6)%, which was significantly lower (p less than 0.01) than that of 91.2 (7.7)% in the non-pigmented group. The plasma oestradiol concentrations in the mothers who later delivered pigmented placentae were significantly lower from 32 weeks of gestation onwards, and did not continue to rise in the last trimester as they did in the non-pigmented group. The last trimester appears to be the critical time for protection of the foeto-placental unit against malaria. Anti-malaria chemoprophylaxis should be given to all pregnant women.