The chances of having a third child with a cleft lip and palate are not great. Cleft lip and palate in the second child is related to a variety of factors such as genetic factors, viral infections that occur during pregnancy, and malnutrition. 1. Genetic factors: If the cleft lip and palate of the second child is caused by genetic factors, the chance of the third child suffering from cleft lip and palate is greater. 2. Viral infections: If a pregnant woman is infected by a virus during the pregnancy of her second child, especially by the rubella virus, it is easy to cause the fetus to suffer from cleft lip and palate; if she pays attention to the prevention of viral infections when she is pregnant with her third child, the fetus will not suffer from cleft lip and palate in general. 3. Malnutrition: If a pregnant woman has severe gestational vomiting or is paranoid about eating, resulting in a lack of calcium, phosphorus, iron and various vitamins in the body, it will induce the fetus to have a cleft lip and palate, and the pregnant woman pays attention to supplementing the nutrition in time when she is pregnant with her third child, and the third child will not suffer from a cleft lip and palate. During pregnancy, the pregnant woman should pay attention to do a good job of maternity examination, and pay attention to rest, avoid staying up late and overwork, nutrition should be balanced, more protein, vitamins and other nutrients, mood to be stable, maintain a good state of mind. Pregnant women with illnesses should be treated in a timely manner, careful use of medication, and should pay attention to the prevention of viruses. Pregnant women should seek timely medical treatment once they develop adverse symptoms.