The human placental bed in health and disease

The morphology of the human placental bed is reviewed. The pathological features seen in spontaneous abortion, pregnancy-induced hypertension, intrauterine growth retardation, placenta accreta and postpartum haemorrhage suggest that abnormal placentation may be a common feature. A defect in the normal materno-trophoblastic interaction is implicated in the pathogenesis of abnormal placentation.