In the clinic, we often encounter children with coughs, colds, bronchitis or pneumonia who are being treated with ultrasound findings of incomplete foramen ovale without other structural cardiac abnormalities. The parents are baffled by this finding. They ask the doctor: How can our child have heart disease when he or she has always been normal, growing, playing sports and even going to kindergarten no different from other children, and is even crazier than his or her peers? Some of them even ask: Our child was examined at the maternity hospital from the beginning of her pregnancy, but the doctor never said that there was something wrong with the child, so is it possible that the doctor did not detect it and delayed the child? In this regard, I feel it is very important to talk with you about simple patent foramen ovale, how it is formed, what are the effects, and whether it needs to be treated, and other little knowledge about the disease that parents are concerned about. (1) What is patent foramen ovale? During the embryonic period, the foramen ovale is a vital channel for the normal development of the fetus, through which the mother’s nutrients are smoothly transported to the left ventricle of the fetus, providing the necessary nutrients for fetal growth and development. In other words, during the fetal period, all the foramen ovale is open and all the foramen ovale is unclosed; he is a normal structure and there is no problem that cannot be detected during pregnancy. When the child is born, with the first cry, the pressure in the child’s left atrium rises, causing the primary septum on the left side to partially adhere to the secondary septum on the right side, and functional closure occurs, and generally by 3 months of age, the foramen ovale is closed in the majority of children. (2) What is the effect of unclosed foramen ovale? The unclosed foramen ovale has no effect on the child’s heart function, so even if the child is found to have unclosed foramen ovale, there is no need to panic, the child can play, move around and go to school like children of the same age, only clinical follow-up and annual cardiac ultrasound is needed. Overseas statistics have found that about 20%-25% of adults can be found with incomplete closure of the foramen ovale, leaving a very small gap, i.e., the foramen ovale is not closed. (3) Does oval foramen insufficiency need treatment? In children, the effect of oval foramen insufficiency on blood flow is small, and murmurs can rarely be heard on clinical auscultation, so early surgical treatment is generally not emphasized. However, it is now believed that foramen ovale insufficiency may be associated with unexplained migraine, transient ischemic attack, thrombosis, etc. Therefore, early surgical intervention is recommended if these symptoms are present in children. Through the above description, parents should understand that: foramen ovale insufficiency is the life channel connecting the fetus and the mother during fetal life, even if the child has foramen ovale insufficiency, it usually does not need treatment, only the child has unexplained headache, transient ischemic attack, sudden syncope, and thrombosis, etc., which need early intervention.