An ultrastructural study of utero-placental spiral arteries in hypertensive and normotensive pregnancy and fetal growth retardation.

Uteroplacental spiral arteries in placental bed biopsies and placentas form 80 pregnancies were studied by light and electron microscopy; of these 30 were complicated by fatal growth retardation(less than 10th centile) and 45 by hypertension during pregnancy. The physiological changes of the spiral arteries and the vascular pathology present in hypertensive pregnancy and fetal growth retardation were investigated. In normotensive pregnancies complicated by fetal growth retardation, the physiological changes of pregnancy frequently did not extend beyond the decidual segments of the utero-placental arteries. In pregnancies complicated by pre-eclampsia, the physiological changes of pregnancy were not always restricted to the decidual segments of the utero-placental arteries. Atheromatous-like lesions of similar morphology were found in spiral arteries from both normotensive and hypertensive pregnancies complicated by fetal growth retardation. No arteriopathy was found which was specific for pre-eclampsia.