Importance of a detailed anomaly scan after a cfDNA test indicating fetal trisomy 21, 18 or 13.

This study suggests that a detailed ultrasound examination performed after a cfDNA result that is high-risk for one of the common autosomal trisomies adds significantly to establishing an individualized risk assessment. This is particularly true in cases with a high-risk result for trisomies 18 or 13.