Objective:

To evaluate the prenatal findings, associated anomalies, and prognosis of right aortic arch (RAA) anomalies.

Material and Methods:

All cases referred for detailed ultrasonography and fetal echocardiography between October 2006 and July 2009 were systematically examined for aortic arch anomalies and associated cardiac and extracardiac anomalies. Prenatal findings of all cases with aortic arch anomalies and intracardiac and extracardiac findings were prospectively registered in an electronic database that included fetal echocardiography. Outcomes of the cases were collected postnatally from the patients’ obstetricians, neonatal unit archieves, and pediatric cardiologists.

Results:

We detected 12 cases of RAA (0.37%; n=12/3200). Mean gestational age at diagnosis was 24 weeks (range, 21–33 weeks). Of the 12 cases of RAA, five (41.7%) had a major cardiac defect, including tetralogy of Fallot (n= 3), atrioventricular septal defect (n=1), and ventricular septal defect (n=1). An extracardiac anomaly was observed in three cases (25%). The fetal karyotype was trisomy 21 in one case with increased nuchal translucency (6.6 mm). Microdeletion 22q11 analyses performed in three cases were normal. The postnatal courses of the cases with isolated RAA were uneventful. Two cases associated with major cardiac and extracardiac anomalies were lost in the early neonatal period. The case of trisomy 21 was terminated. The other four cases of RAA with an associated cardiac anomaly are currently in follow up.

Conclusion:

Aortic arch anomalies, particularly RAA, can be diagnosed by fetal echocardiography. The prognosis for isolated RAA is relatively good compared with that for RAA with associated anomalies.

Keywords: Right aortic arch, aortic arch anomaly, fetal echocardiography, fetus, prenatal diagnosis