Malaria and pregnancy: Placental cytokine expression and its relationship to intrauterine growth retardation

Malaria infections during pregnancy can lead to the delivery of low-birth-w eight infants. In this study, cytokine mRNA was measured in placentas from 23 malaria-infected and 21 uninfected primigravid women who had delivered i n Mangochi, Malawi, a region with a high rate of transmission of falciparum malaria. Significantly increased expression of interleukin (IL)-1 beta, IL -8, and tumor necrosis factor (TNF)-alpha and decreased expression of IL-6 and transforming growth factor-beta 1 were found in malaria-infected compar ed with uninfected placentas. TNF-alpha and IL-8 were produced by maternall y derived hemozoin-laden placental macrophages. Increased TNF-alpha express ion was associated with increased placental hemozoin concentrations. Increa sed TNF-alpha or IL-8 expression in the placenta was associated with intrau terine growth retardation hut not with preterm delivery. The results sugges t that malaria infections induce a potentially harmful proinflammatory resp onse in the placenta.