A very rare fetal echocardiography diagnosis: Sinus venosus type atrial septal defect with pulmonary venous return abnormality

Atrial septal defect is diagnosed in 1 per 1500 live births. It is classified into four subtypes according to the location. We present the prenatal diagnosis of a fetal sinus venosus type atrial septal defect (SV-ASD), which is very rarely diagnosed in the prenatal period. We present the prenatal diagnosis of a fetal sinus venosus type atrial septal defect (SV-ASD), which is very rarely diagnosed in the prenatal period. The main sign of superior vena cava type (SVC) sinus venosus atrial septal defect is the SVC overriding on the interatrial septum (arrow) on the bicaval view. This defect is associated with other venous abnormalities like pulmonary venous return abnormality and agenesis of ductus venosus. (RA: right atrium, LA: left atrium). image