PRENATAL IDENTIFICATION OF ABERRANT RIGHT SUBCLAVIAN ARTERY IN ISOLATION: THE NEED FOR FURTHER GENETIC WORK-UP?

The objective of this study was to evaluate the association between aberrant right subclavian artery (ARSA) and chromosomal abnormalities. The study included 5211 women having attended our unit for fetal anatomic screening and fetal echocardiography from August 2016 until February 2019. After diagnosing ARSA, prenatal invasive testing was discussed with the patients. ARSA affected fetus was determined in 57 cases; of these, there were 38 cases of isolated ARSA and 19 cases of non-isolated ARSA but associated with soft markers and fetal anomalies. Nineteen patients underwent amniocentesis; Down syndrome was determined in two women, both of them from the non-isolated ARSA group, with fetal hydrops, atrioventricular septal defect and esophageal atresia. Fifteen of 38 patients who declined prenatal diagnostic testing, accepted karyotype analysis after delivery and none of these 15 cases had chromosomal abnormalities. Identification of ARSA should be followed by detailed ultrasound examination to ensure that there are no accompanying soft markers and/or structural defects. Isolated ARSA may not be an indication for karyotype analysis or 22q11.2 microdeletions. Non-ARSA implies a strong predictor of aneuploidy, and when additional findings are detected, invasive testing should be offered to the parents. The association between isolated ARSA and genetic disease should be evaluated in large powered prospective studies.