Antenatal diagnosis of double outlet of right ventricle without extracardiac anomaly: a report of 4 cases.

Four fetuses were diagnosed antenatally with double outlet of right ventricle (DORV) at 17, 20, 26, and 28 weeks' gestation, respectively, using 2-dimensional sonography. Chromosome study was normal in all 4 cases, and there were no extracardiac abnormalities. The sonographic diagnoses were based on the following findings: (1) arising of the 2 great vessels predominantly from the right ventricle; (2) the presence of bilateral coni; and (3) parallel direction of the 2 vessels rather than the normal perpendicular course. Two cases were terminated electively with postnatal autopsy confirmation; the other 2 cases were closely monitored throughout pregnancy and underwent normal vaginal delivery at term and subsequent surgical correction with good outcome. In conclusion, DORV can be readily diagnosed in utero by checking outflow tract even without 3-dimensional sonography and in the absence of obvious risk for congenital heart defects.