Many parents find a small hole in the atrial septum of their child’s heart, mostly under 5 mm in diameter, during a physical examination of their newborn baby and request surgery for their child. In fact, this condition is medically known as patent foramen ovale (PFO for short). The foramen ovale is a vital channel necessary for the development of the fetus, and it is through this channel that blood from the mother’s umbilical vein enters the left side of the fetus’ heart and is then distributed throughout the body to provide the oxygen and nutrients needed for fetal development. At birth, with the first cry, the pressure in the left atrium rises and the oval fossa valve is pressed against the edge of the oval fossa to form a functional closure, which is usually complete anatomically until 5 to 7 months after birth. Therefore, it is possible that the foramen ovale may remain open up to one year of age, and there may be a small shunt, or even 5%D10 % of individuals with the foramen ovale remaining open and unclosed for life, but with no effect on cardiac hemodynamics. Therefore, a patent foramen ovale in infancy is a normal physiological phenomenon, not a precordial disease, and usually does not require surgery. However, if the central atrial septal defect is large, greater than 8D10 mm, with a large fractional flow, it is called a central atrial septal defect and requires surgical repair. The timing of surgery should be aimed to be done when the child is 2D4 years old. The chances of non-closure of the foramen ovale may be increased if the mother has contracted a virus during pregnancy, has been exposed to radiation or has taken some medication that impairs fetal development. Therefore pregnant women should avoid the above mentioned conditions. Ultrasound has the advantages of being convenient, noninvasive, highly accurate, and repeatable in diagnosing oval foramen nonunion in newborns, which can provide an accurate basis for clinical diagnosis and treatment. In recent years, it has been found that foramen ovale is closely related to unexplained cerebral embolism, diving decompression sickness, migraine and other diseases. Therefore, some scholars believe that repair treatment should be performed for people with a history of unexplained cerebral embolism, divers, astronauts and people with intractable migraine combined with foramen ovale non-occlusion.