Pregnant women that smoke cigarettes on a daily basis can greatly harm their fetus. The Tobacco smoke in cigarettes greatly reduces fetal growth through the presence of nicotine, carbon monoxide, hydrogen cyanide, cadmium and various other aromatic hydrocarbons, but the two most dangerous chemicals that are found in cigarettes are nicotine and carbon monoxide. Nicotine causes the babies heart rate to speed up, reduces placental vascularisation, constricts the placental arteries, and thickens the endothelium of placental blood vessels. This cre ....