Prenatal diagnosis of isolated congenitally corrected transposition of the great arteries.

Congenitally corrected transposition of the great arteries (ccTGA) is a rare cardiac defect characterized by the atria connecting with anatomically discordant ventricles and the ventricles connecting with discordant and transposed great arteries, which allows hemodynamic compensation. Most patients with ccTGA have associated intracardiac anomalies, which could be a diagnostic clue, whereas isolated forms are infrequently diagnosed during the neonatal period and in utero. We describe a fetus that was diagnosed with ccTGA and without additional cardiac anomalies at 25 weeks of gestation. The parallel course of the great arteries discovered during a routine obstetric scan indicated this rare cardiac anomaly. Further detailed examination of the ventricular morphology helped to confirm the diagnosis. Despite hemodynamic compensation, the long-term prognosis of ccTGA is uncertain because of the possible development of arrhythmias or heart failure later in life. Our findings showed that fetal echocardiography can detect prenatal ccTGA.