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.