ABSTRACT
Apoptosis, or programmed cell death, is an active process by which dysfunctional cells are eliminated to maintain normal tissue function. Apoptosis is important for normal placental development. Apoptotic cells have been identified in both the maternal and fetal compartments of the placenta during normal pregnancy. The aim of this work was to study the physiologically occurring phenomenon "apoptosis" in full term normal placentas compared with diabetic ones. Ten multipara full term pregnant women were used in this study. They were divided into two groups, control group contained five normal women, and diabetic group, contained five diabetic women treated with insulin during pregnancy. Placental specimens were obtained immediately after normal vaginal delivery and were processed for both light and electron microscopic examination. Light and electron microscopic examination of normal specimens showed the normal structure of chorionic villi of full term placenta. Apoptotic cells were detected normally in all layers of placental villi. Light microscopic examination, of the diabetic placental specimens showed many degenerated chorionic villi. Its, syncytiotrophoblastic covering was thin, degenerated and necrotic. Syncytial knots were more frequently observed. Collagen fibers were increased in stroma of the degenerated villi. Fetal capillaries were dilated, congested and lined by degenerated endothelial cells. Apoptotic cells appeared more numerous in all layers of diabetic placental villi compared to controls. Electron microscopic examination of diabetic placental villi revealed destruction of syncytial microvilli. Syncytial cytoplasm was markedly vacuolated. Trophoblastic basement membrane was irregularly thickened. Marked increase of collagen fibers was observed in the villous stroma. Fetal capillaries were extremely dilated and were lined by degenerated endothelial cells. Apoptotic cells were more frequently seen in all layers of placental villi compared to normal ones. In conclusion, apoptosis occurred physiologically in normal placenta and increased dramatically in diabetic placenta