Chronic placentitis--a clinicopathological study.

Between 1978 and 1983 1240 singleton placentas were examined macroscopically and histologically. In 82 cases (6.6%) a "chronic placentitis" was diagnosed. The pathognomonic inflammatory foci were localized within the placental villi. The vast majority showed mixtures of both fibrohistiocytes and lymphoid cells, which were occasionally interspersed with plasma-cells. The clinical data relating to 67 placentas were correlated retrospectively with the degree of inflammation. 46 showed mild and 21 moderate to severe chronic placentitis. In both of these groups the proportion of preterm deliveries and cases with preeclampsia was equally high. With increasing severity of chronic placentitis, however, there was a significant reduction in weight and size of both, placenta and infant, and the incidence of perinatal asphyxia was significantly raised.