Bevilacqua E, et al. – This article was composed with the goal to study patient choice in regards to testing for sex chromosome aneuploidy (SCA) and the performance of cell–free DNA (cfDNA) screening for SCA. More than half of the patients undergoing cfDNA aneuploidy screening also opted for SCA testing, but they were less likely to do so in the presence of an increased risk of trisomy. SCAs involving the X chromosome had a lower positive predictive value (PPV) than those involving the Y chromosome.