Smoking can have an impact on pregnancy, as follows: First, smoking can cause fetal malformations, fetal arrest, abnormal fetal development, and even cause miscarriage. Secondly, inhaling nicotine when smoking can cause abnormal blood oxygen concentration in pregnant women, which can lead to fetal hypoxia and also affect the circulation of the uterine vessels, which can cause damage to the circulatory system and brain development of the fetus. Third, the body of pregnant women is sensitive, smoking may cause allergies, asthma and other diseases. Fourth, smoking can cause nausea and vomiting in pregnant women, which can affect the intake of nutrients and cause malnutrition in the fetus. Fifth, smoking by the mother during pregnancy can cause the baby to be born with a weak constitution and more prone to bronchitis, otitis media, allergic rhinitis, asthma and other diseases. It can also affect the baby’s rate of development, height and weight, which may be lower than normal children of the same age. It can be confirmed that cigarettes contain carcinogenic substances, which are not good for the pregnant woman herself or the baby in her belly, and it is recommended to quit smoking.