Aberrant right subclavian artery at 11 + 0 to 13 + 6 weeks of gestation in chromosomally normal and abnormal fetuses

Abstract

Assessment of the position of the right subclavian artery is feasible at the 11 + 0 to 13 + 6-week scan and ARSA is more common in chromosomally abnormal than normal fetuses. However, ARSA in the first trimester is unlikely to be a useful marker of trisomy 21.