Smoking during breastfeeding may have direct effects on the newborn, such as directly stimulating the respiratory system; it may also have indirect effects, such as affecting the digestive system and nervous system. 1. Direct effects: If a woman smokes during breastfeeding, the smoke will be directly absorbed by the baby. As the baby’s respiratory system is very fragile, smoke and other toxic substances may directly stimulate the respiratory tract and a series of respiratory diseases, increasing the incidence of bronchitis, pneumonia and other diseases. 2. Indirect effects (1) Digestive system: after a breastfeeding woman smokes, nicotine and other toxic substances can be absorbed by the baby through breast milk, which can easily cause abdominal pain and anorexia in the baby. (2) Nervous system: If the baby is exposed to second-hand smoke for a long time, it will also affect the baby’s hearing, sense of smell and brain cell development. It can be seen that smoking during breastfeeding has a great impact on the baby, and women should be prohibited from smoking during breastfeeding. At the same time, men should not smoke indoors to avoid second-hand smoke to the baby.