Smoking is prohibited during pregnancy, there are a lot of harmful substances in cigarettes, easy to have adverse effects on the fetus and the mother. A, the impact on the fetus: 1, fetal malformations: cigarette smoke contains lead, cadmium and other metal toxins, which can cause neonatal malformations through the placenta from the mother into the fetus, such as cleft palate, cleft lip, congenital heart disease, anencephaly, etc.; 2, intrauterine growth retardation: cigarettes contain nicotine, carbon monoxide and other harmful substances, which can affect the placental blood circulation by reducing the maternal physiological process of nitric oxide, thus The mother’s supply of nutrients and fetal use of nutrients caused by the obstacle, which subsequently leads to intrauterine growth retardation, and in serious cases can cause pregnant women to deliver low birth weight newborns. In addition, cyanide contained in cigarettes can be combined with sulfur amino acids in the mother, resulting in reduced vitamin B12 content, which affects the development of the fetus, and in serious cases can cause neonatal mental retardation; 3, miscarriage and preterm delivery: harmful substances in cigarettes can stimulate the placenta, resulting in fetal hypoxia and abnormal vasoconstriction, causing early embryonic arrest and premature calcification of the placenta, which can lead to preterm abortion and preterm delivery. Premature birth. Second, the impact on pregnant women: 1, respiratory diseases: because smoking can lead to a decrease in the immune system of pregnant women, so it is easier to contract lung diseases, such as bronchitis, bronchitis, pneumonia and interstitial fibrosis; 2, pregnancy complications: smoking during pregnancy can make pregnant women coronary vasoconstriction, may cause blood pressure, lipid elevation and coronary atherosclerosis and other conditions, which in turn increases pregnant women The probability of hypertension, hyperlipidemia and preeclampsia during pregnancy is increased. It is recommended that pregnant women take the necessary steps to quit smoking during pregnancy for the health of the fetus and the mother, and that they avoid exposure to secondhand smoke and stay away from smoking environments as much as possible.