ABSTRACT
Passive exposure to tobacco smoke causes ultrastructural changes in placental vasculature. It was endeavoured to observe under the light microscope, the endothelial cells of the capillaries and to look for microscopic changes in the vasculosyncytial membranes in the terminal villi of placentae of passive smokers exposed largely to bidi smoke. To study effect of passive smoking on placental vasculature a total of 150 placentae were selected from healthy full term gravidas with no history of tobacco use. They were divided into two group viz; passive smokers (n=87) and non passive smokerscontrol (n=63). Three micron thick sections were cut, stained and examined under light microscope. The study revealed that endothelial cells of stromal capillaries of the placental villi were oedematous resulting in irregular capillary lumina (p=0.0007) and vasculosyncytial membrane was significantly absent in terminal villi of passive smokers in comparison to control (p=0.0000).