The placenta in malaria: Mechanisms of infection, disease and foetal morbidity

There is still much to discover about the reasons for the increased susceptibility of pregnant women to malaria or the pathogenesis of placental malaria. More systematic and detailed examination of the placenta may help. In many ways, the placenta can be seen as the flight recorder of the pregnancy; by examining it carefully it should be possible to tell much about how smooth a 'flight' the mother and baby experienced. It is hoped that, by probing the secrets of this 'squishy black box', the causes of adverse effects in pregnancy are elucidated, and the safe 'travel' of babies and their mothers in the future is ensured. In this review, the features of parasite accumulation in the placenta, parasite adherence, and hormonal and inflammatory responses to placental malaria are discussed, focussing on infection with Plasmodium falciparum. The results of recent research indicating an interaction between HIV and malaria in pregnancy are summarized. Ten questions for basic researchers are posed. The answers may help direct future efforts to control malaria in pregnancy.