Cleft lip and palate can be detected at 10 to 24 weeks of pregnancy. Cleft lip and palate can be detected at 18 to 24 weeks of pregnancy by 4D ultrasound, which can visualize the congenital tissue defects in the fetal lip as well as the alveolar ridge, and provide early diagnosis of fetal malformations such as cleft lip, cleft palate, cardiovascular malformations, and skeletal development. Cleft lip and palate are congenital oral and maxillofacial malformations with varying degrees of clefts in the lip or palate due to facial dysplasia, and are not fully fused until at least 12 weeks to 14 weeks or more. It is difficult to tell when the fetus is too small, and the best time to screen is between 20 and 24 weeks of gestation. During pregnancy, patients should take folic acid consistently, maintain a balanced diet, stay away from polluted and radioactive environments, and have regular ultrasound tests to detect problems early and make reasonable treatments.