OP16.10: Prenatal diagnosis of aberrant right subclavian artery (ARSA) in unselected population: our own experience

Abstract

The aim of our study was to analyses all cases with aberrant right subclavian artery (ARSA) and its association with chromosomal and other congenital malformations. 2863 fetuses between 12 and 34 weeks were examined by ultrasound in our centre between January 2015 and March 2017 by one examiner. ARSA was assessed in the axial plane on the level of three vessels and trachea view. ARSA was identified in 33 fetuses. ARSA was an isolated finding in 13 (39%) fetuses and non-isolated in 20 (60%) fetuses. In 9 (27%) of these 33 cases ARSA associated with congenital cardiac anomalies such as AVSD, coarctation of aorta, vascular ring, right aortic arch, HLHS, bilateral superior vena cava and tetralogy of Fallot (2). Additional ultrasound findings such as an occipital encefalocele, hemivertebra (2 cases), diastematomyelia, partial agenesis of corpus callosum, cavum velli interposity, tricuspid regurgitation, single umbilical artery, large NT (3 cases), abnormal hands, retrograde ductus venosus blood flow were present in 14 (42%) fetuses. 5 (15%) of these of 33 were aneuploidies: Trisomy 21 was diagnosed in 4 fetuses, Trisomy 18 in 1 fetus. 22q11 microdeletion was detected in 1 fetus. All women with isolated ARSA were recommended to have a non-invasive prenatal diagnostic test. No cases with Down syndrome were detected in all 13 fetuses with isolated ARSA. Isolated ARSA does not seem to be associated with a significantly increased risk of aneuploidy, however using of a non-invasive diagnostic test might be discussed. When ARSA is identified a detailed anatomy scan should be recommended. An invasive procedure with genetic diagnosis should be discussed when additional ultrasound abnormalities or risk factors for aneuploidy are found.