[The placenta and malaria. A morphologic, parasitologic and clinical study (author's transl)].

In 115 consecutive placentae from an unselected population living in a high malaria endemic region (Franceville, Haut-Ogooué, Gabon, 40 (35%) have the peculiar lesions of maternal plasmodium infection. The lesions show considerable histological variation but the following features are constant: a) deposits of variable amounts of malarial pigment and b) excess of perivillous fibrinoid. Accumulation of maternal erythrocytes with parasites, concentration of macrophages in intervillous spaces and villities are inconstant. In addition, splitting and segmental thickening of the trophoblast basal membrane with occasional aggregations of dense fibrillary structures are found at ultrastructural level. 56% of the mothers have Plasmodium falciparum (94%) or Plasmodium malariae in their peripheral blood. Placental lesions have been found only in 65% of the cases with peripheral parasitemia. Although Plasmodium are present in 35 (87%) placentae, no parasites have been found in the cord blood. The difference between the mean birth-weight of full-term neonates from mothers with placental lesions (n = 38) or with normal placenta (n = 54) is 220 g. This difference is statistically highly significant (p less than 0,001). It appears that the low mean birth-weight is not related to the high percentage (39%) of primipare in the infected group but, in all probability, to the placental lesions.