Congenital heart disease can be detected during pregnancy, and with the rapid development of prenatal diagnostic technology nowadays, most of the congenital heart diseases can be diagnosed through prenatal ultrasound such as 4D ultrasound and fetal heart ultrasound. Fetal heart ultrasound can observe the four chambers of the heart, the large blood vessels for structural malformations and the blood flow of the heart for abnormalities under ultrasound, and is currently the preferred method of examination. However, there are many small abnormalities, such as microscopic defects of the ventricular septum and atrial septum, which are easily missed and can be ruled out after delivery by neonatal cardiac auscultation and cardiac ultrasound, such as microscopic defects of the atrial septum and ventricular septum and arteriovenous ductus arteriosus after birth, which can gradually heal as the child grows up.