Tobacco and alcohol have a negative impact on pregnancy, not only endangering the health of pregnant women, but also on the development of the fetus, such as developmental malformations, premature birth, low birth weight babies, etc. A, the impact of pregnant women themselves: 1, prone to gynecological inflammatory diseases: tobacco contains nicotine, carbon monoxide and other harmful substances, wine contains alcohol and other components, often smoking, drinking pregnant women, more likely to suffer from gynecological inflammatory diseases, such as cervicitis, pelvic inflammatory disease; 2, affect the hemoglobin content: pregnant women smoking or passive smoking has a certain impact on the maternal hemoglobin content, anemia; 3, damage to the liver: alcohol in the Most of the alcohol in the body through the liver metabolism, if pregnancy still do not pay attention to control, will cause pregnant women liver cells metabolic disorders, resulting in fatty liver or alcoholic liver. Second, the impact on the fetus: 1, the first trimester of pregnancy is a critical period for the differentiation of embryonic cells, if pregnant women smoke inordinately, the light will lead to fetal growth restriction, developmental malformations, serious cases can lead to premature birth, miscarriage; 2, alcohol has a negative impact on the fetus, if pregnant women drink too much alcohol, may lead to impaired fetal intelligence development after birth, fetal alcohol syndrome, may also make the newborn stunted, low weight, special It may also lead to poor growth, low weight, special facial features and even deformities. In order to effectively avoid the adverse effects of tobacco and alcohol on pregnant women and their fetuses, both men and women should quit smoking and drinking and stay away from unfavorable environments.