There is an oval foramen open between the left and right atria of the fetal heart. The oval foramen usually closes within the first year of life, so the oval foramen is unclosed in newborns and infants. If the foramen ovale does not close in children older than 3 years of age, the foramen ovale is not closed. The patent foramen ovale is one of the congenital heart diseases in pediatric patients, but the patent foramen ovale is not a disease state in newborns. The human heart is divided into four chambers, including the left atrium, right atrium, left ventricle, and right ventricle, and the septum between the left and right atria is called the interatrial septum. The foramen ovale is located in the atrial septum. During fetal life, the lungs have no respiratory function and are in a state of non-distension. Pulmonary blood flow enters the descending aorta from the arterial duct and is sent to the placenta for oxygen exchange through the umbilical artery. Therefore, the pulmonary circulation returns very little blood to the left atrium, so the blood returning to the right atrium must be guided by the inferior vena cava valve through the fossa ovalis into the left atrium to accommodate the physiological needs of the special circulation during the fetal period. When the infant is born, with a cry, it begins to rely on its own lungs for respiratory oxygenation, and at this time the foramen ovale closes. If the foramen ovale does not close by the age of 3 years, the foramen ovale is not closed. There is a high prevalence of patent foramen ovale in the population, with studies in the literature showing that approximately 25-30% of the population has patent foramen ovale. However, the disease is usually asymptomatic and does not require specific treatment. If serious complications arise due to patent foramen ovale, prompt treatment is required.