Women who smoke during pregnancy may affect the normal growth and development of the fetus, leading to premature birth, miscarriage or fetal development malformations, so it is advisable not to smoke during pregnancy and to go to the hospital for maternity checkups on time and take measures under the guidance of a professional doctor to prevent the adverse consequences of smoking. Tobacco contains many toxic substances such as nicotine, hydrocyanic acid and pyridine aromatic compounds, which can be absorbed into the mother’s body along with the smoke and enter the blood circulation, lowering the blood oxygen level in the mother’s body. Because the placenta is connected to the mother’s body, it can also reduce the amount of oxygen absorbed by the placenta, which can lead to intrauterine hypoxia, slow growth, neurological or organ malformations, and increase the chances of fetal miscarriage. It also reduces the normal defense function of the pregnant woman and increases the risk of various diseases, and may cause hypertensive disorders during pregnancy. If you need to continue your pregnancy, you should go to the hospital in time to have a Down’s syndrome screening at 15-20 weeks of pregnancy to check the development of the fetus’ intelligence, or a 4D ultrasound at 22-26 weeks of pregnancy to rule out fetal developmental malformations. Folic acid supplementation is also required under the guidance of a medical professional to prevent neural tube abnormalities and other diseases in the fetus. If there is no need to continue the pregnancy, the pregnancy can be terminated if necessary after communication with the doctor. For pregnant women, in addition to prohibiting themselves from smoking, they should also pay attention to stay away from second-hand smoke to avoid causing more harm to their body and fetal development.