MALARIC PLACENTAS - A QUANTITATIVE STUDY AND CLINICOPATHOLOGICAL CORRELATIONS

A histological and morphometric study was conducted on 372 placentae o ut of a total 440 delivered in Zanzibar. Fibrin (F), intervillous spac e (IVS) and Villi (V) relative volumes were determined by the point-co unting system and the ratio of syncytium to blood capillaries by the l inear intercept method. Parasitemia load and inflammatory reaction wer e graded semiquantitatively by the use of a 1 mm square grid. Parasiti sed red cells identified active malaria (AM), the presence of malarial pigment only identified east malaria (Phl), and the absence of both c haracterized non-malarial placentae (Nhl). AM(17.87%), PM(21,61%) and NM(60.52%) placentae did not vary significantly in weight. Newborns fr om AM had a significantly lower weight than those from Pill and Nhl. P eripheral and placental parasitemia were not coincident. Placental par asitemia load increased parallel with birthweight. The latter decrease d with the increasing severity of the inflammation, particularly with the prevalence of lymphocytes in the IVS. Significantly increased volu me off was found in AM and PM placentae, while no significant variatio n was noticed in IVS and V volumes. The syncytium/capillaries ratio wa s significantly increased in AM. We conclude that low birthweight in m alaria is linked to IVS inflammation but not to F deposits or parasite mia load. Non-leukotactic lymphokines might play some role. Morphologi c aspects bespeak for a less mature placenta than expected and this mi ght represent an adaptive change.