Prenatal detection of foramen ovale obstruction without hydrops fetalis.
 A case of prenatal echocardiographic diagnosis of obstruction of the foramen ovale is described.
 Presentation was the ultrasound detection of unexplained marked right atrial and right ventricular dilation without fetal hydrops.
 It is speculated that fetal outcome depends on the severity and time of onset of foramen ovale obstruction in utero.
