Ultrastructural investigation of the effects of cigarette smoking on the human placenta

Abstract

SummaryPlacental villi from all three trimesters of pregnancy, from 60 non-smoking women and 171 who smoked cigarettes were examined. Numbers of syncytial knots increased and syncytial buds decreased as pregnancy proceeded. More vascular-syncytial membranes and less Hofbauer cells and Langhans cells were present in the second and third trimesters. Numbers of avascular villi and cell islands diminished through pregnancy. In the smokers, in the third trimester, syncytial knots were increased, and syncytial buds decreased; there were less vasculo-syncytial membranes. Hofbauer cells were decreased and Langhans cells increased in the smokers.By electron microscopy, the villi from smokers had abnormalities of the microvilli, focal syncytial necrosis, decreased syncytial pinocytotic activity, thickening of the syncytial coarse and smooth endoplasmic reticulum, and thickening of the trophoblastic basal lamina. There was increased collagen in the villous stroma and degenerative epithelial changes in the fetal capi...