Isolated levocardia: prenatal diagnosis and management.

Isolated levocardia (IL) is a rare condition of situs anomaly in which there is a normal left-sided heart (levocardia) with dextro position of the abdominal viscera. IL has been reported in children and adults with complex cardiac defects, whereas there are only few published reports regarding the prenatal diagnosis of IL. We report two prenatal cases of IL diagnosed by ultrasonography and magnetic resonance imaging (MRI). In both cases, fetal cardiac function remained within the normal range throughout pregnancy, and no treatment for the heart was required after birth. For the dextro position of abdominal viscera, one case was followed without any surgical procedure, but the other case required prophylactic operation due to malrotation of the small intestine. Although the prognosis of IL largely depends on the severity of associated cardiac anomaly, future bowel obstruction caused by intestinal malrotation may also be life-threatening. In this respect, prenatal diagnosis of IL is important, even when there is no associated cardiac structural anomaly. If IL is suspected in routine fetal ultrasonography, MRI may be recommended to obtain more detailed information on the anatomy of abdominal viscerae, and careful observation for bowel problems is required, especially after oral nutrition is started.