Fetal ascending aorta widening 6mm is abnormal, belongs to the aortic dilatation, this condition may be due to Mafontaine syndrome and so on, it is recommended that parents should pay attention to this condition, if necessary, also need to be induced labor. The disease is also called Marfan syndrome and limb elongation syndrome, etc. At the onset of the disease, cardiovascular system diseases such as entrapment aneurysm and mitral valve insufficiency may occur, and it may also cause aortic dilatation. If it is not treated in time, it may lead to developmental problems of the fetus, such as symptoms of chicken breast and spinal deformity, which will have a great impact on the development of the fetus in the future. It is recommended to go to the hospital regularly to review the condition, and the doctor will dynamically adjust the subsequent treatment plan according to the condition.