Impact of Placental Plasmodium falciparum Malaria on Pregnancy and Perinatal Outcome in Sub-Saharan Africa: I: Introduction to Placental Malaria

Placental malaria is one of the major features of malaria during pregnancy and has been widely used as a standard indicator to characterize malaria infection in epidemiologic investigations. Although pathogenesis of placental malaria is only partially understood, placental sequestration of Plasmodium falciparum results in the accumulation of parasitized erythrocytes in the intervillous space, infiltration by inflammatory cells, and release of pro-inflammatory mediators, which cause pathologic alterations that could impair materno-fetal exchanges, often resulting in adverse pregnancy outcome. In this report, the impact of placental malaria on pregnancy and perinatal outcome is reviewed using data from studies conducted in sub-Saharan Africa. Generally, placental malaria was associated with increased risk of maternal anemia, HIV infection, and maternal mortality, with younger women and primigravidae more likely to be affected. A variety of adverse perinatal outcomes, including low birth weight, preterm delivery, intrauterine growth retardation, reduced fetal anthropometric parameters, fetal anemia, congenital malaria, increased mother-to-child HIV transmission, and perinatal mortality, were associated with placental malaria. There were, however, conflicting reports on whether the risk of these adverse perinatal outcomes associated with placental malaria were statistically significant. There is a clear need to strengthen the malaria prevention and intervention measures for pregnant women in sub-Saharan Africa.