Right Aortic Arch Diagnosed Antenatally: Associations and Outcome in 98 Fetuses

Study Questions:

What are the characteristics, associated conditions, and outcome of right aortic arch (RAA) detected in fetal life?


A retrospective review was performed of all cases of RAA diagnosed at a single tertiary center between January 2004 and December 2012.


A total of 16,332 fetal echocardiograms were performed during the study period. Of 98 fetuses with RAA, 71 had associated congenital heart disease and 28 had normal intracardiac anatomy. The vast majority of associated intracardiac lesions were conotruncal anomalies, occurring in 77.5% of fetuses with RAA and congenital heart disease. Associated vascular anomalies included aberrant left subclavian artery in 18.4%, double aortic arch in 6.1%; vascular ring was confirmed after birth in 11.1% of cases.


Detailed fetal cardiac and extracardiac examination should be undertaken in all cases of RAA. The prognosis of RAA is dependent on severity of associated intracardiac and extracardiac anomalies.


RAA may be associated with significant intracardiac congenital heart disease, specifically conotruncal anomalies. RAA is particularly significant when associated with a vascular ring leading to mechanical compression of the airway and/or esophagus. The diagnosis may sometimes be delayed, as the respiratory or gastrointestinal symptoms may not immediately prompt investigation for vascular anomalies. In this series, prognosis for patients with isolated RAA was good, as it was generally asymptomatic and rarely associated with chromosomal abnormalities. The incidence rate of 0.6% reported in this study is not likely indicative of the rate in the general population because of referral bias for the study center.

Clinical Topics: Congenital Heart Disease and Pediatric Cardiology, Congenital Heart Disease

Keywords: Prognosis, Heart Defects, Congenital, Fetus

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