Echogenic atria in a fetus.

We report a case of transmural echogenic atria diagnosed in a fetus at 22 weeks' gestation. Fetal echocardiography showed echogenicity of the right and left atrial free walls, septum secundum, and atrial appendages. Postnatal echocardiography at birth showed borderline echogenicity with absence of echogenicity on follow-up echocardiography. The differential diagnosis, possible causes, and outcome associated with transmural atrial echogenicity are discussed.