Placental changes associated with fetal outcome in the Plasmodium coatneyi/rhesus monkey model of malaria in pregnancy

Term placentas collected surgically from seven Plasmodium coatneyi-infected rhesus monkeys, one abortion, and five controls were evaluated histopathol ogically. The placentas from Plasmodium-infected dams had more significant pathologic changes than those from controls for six parameters (P < 0.05) a nd higher numbers of activated (LN5 + Zymed) macrophages in the intervillou s space (IVS) (P = 0.0173). Total parasite loud (TPL) was defined as the su m of all weekly peripheral infected red blood cell counts for each trimeste r and for the entire pregnancy. High first trimester PLs were more likely t o result in fetal demise (P = 0.0476) or increased placental damage in surv iving infants. As trimester 2-3 TPL increased, so did the number of activat ed macrophages (P <less than> 0.05) and the total malaria pigment scores (P < 0.05). Low birth weight (LBW) and intrauterine growth retardation (IUGR) were associated with high pigment scores and high numbers of activated mac rophages in the IVS. High placental damage scores were not associated with IUGR, LBW. or early infant mortality.