In general, cleft lip can be detected by ultrasound. There are generally more causes of cleft lip, such as genetic factors, environmental factors, nutrient deficiency infection or endocrine disorders, drug factors, physical damage or tobacco and alcohol. Depending on the type, different treatments are chosen. In case of unilateral cleft lip, the best time for surgery is usually around 3 to 6 months. To take preventive measures, avoid partial diet during pregnancy, ensure the intake of vitamins or trace elements, keep a calm mind, avoid mental tension, do not blindly use drugs, such as anticonvulsants or histamines, avoid exposure to radiation or microwaves, etc.