Prenatal detection of restrictive foramen ovale.

The foramen ovale is an important communication between the two sides of the heart prenatally, allowing the left ventricle to carry its share of the prenatal circulation and providing flow for growth of left ventricular structures. Restriction of the foramen ovale appears to be a serious disorder of the fetus and can be associated with fetal hydrops, arrhythmias, and other signs of major fetal compromise. This article reviews our experience with restriction of the foramen ovale and provides a summary of the pathologic and echocardiographic literature related to the etiology and effects of restrictive foramen ovale in the fetus.