Neonatal atrial septal defect 1.5mm, not serious, can be self-healing is very likely. Clinical principles: regardless of the size of the atrial septal defect, as long as the child is less than two years old, there is no need for surgical treatment, regular clinical observation can be. When the child is more than two years old, if the atrial septal defect is less than 5mm, you can continue clinical observation, regular cardiac ultrasound to observe the size of the atrial defect can be. If the atrial septal defect is larger than 5mm, and the child often gets pneumonia after a cold, and it does not heal, this time need to do surgical treatment. You can choose the internal patch treatment, if necessary, you can also open the chest to do surgical treatment, need to be decided according to the specific circumstances.