Singleton placentas from 330 consecutive births were examined for size, shape, cord insertion, allanto-chorial vascular pattern and lobes. These factors were considered regarding possible interactions and correlation to pregnancy and perinatal outcome. Marginal cord insertion was correlated to extrachorial and bilobate placenta and to magistral wr mixed allanto-chorial vascular pattern. A paucity of lobes (less than 15) was associated with extrachorial placenta, marginal cord insertion, pre-eclampsia, gestational age less than 38 weeks and small for gestational age infants. The common denominator for abnormal configuration and marginal cord insertion seemed to be the paucity of lobes.