1, genetic factors: cleft lip and palate is a polygenic genetic disease, the normal incidence of 0.10% to 0.17%, but the father suffers from cleft lip, the offspring prevalence rate of about 3%, if the mother suffers from cleft lip, the chances of inheritance to children up to 14%. 2, nutritional deficiencies: vomiting, anorexia and paranoia during pregnancy in women can affect nutritional intake, resulting in deficiencies of vitamins (such as vitamins A, E, B2, B6, C, D), folic acid, and minerals such as calcium, phosphorus and iron. 3, viral infections: In the early stages of pregnancy (within 2 months), viral infections such as viral colds or rubella may become the cause of cleft lip in infants. 4.Drug factors: The drugs that have been clearly caused cleft lip and palate deformities are adrenocorticotropic hormones, anti-epileptic drugs, anti-malignant drugs, anti-allergy drugs, etc. 5.Endocrine disorders: In the early stage of pregnancy (within 8 weeks), if the pregnant woman is emotionally stressed, or for physiological or mental reasons, the secretion of adrenocorticotropic hormone in the body increases, which leads to malformation of the embryo. 6, radiation: early pregnancy if exposed to radiation, there is a risk of mutation of embryonic cells resulting in fetal cleft lip and palate. 7, smoking, alcohol abuse: pregnant women smoking, alcohol abuse can also lead to infants with cleft lip and palate. 8, parental age factor: the incidence of cleft lip and palate has a correlation with the age of the parents, the higher the risk of cleft lip and palate if the age of childbirth is above 35 years old.