Objectives To systematically examine the performance of a detailed ultrasound (US) performed within 14 weeks, following a high-risk cell-free DNA (cfDNA) for trisomy 21 (T21), 18 (T18) and 13 (T13). Methods PubMed, EMBASE and CINHAL were searched up to February 2024. Singleton pregnancies with high chance of T21, T18 and T13 were included. The index test was a detailed US performed within 14 weeks, when either chorionic villus sampling (CVS) or amniocentesis (AC) can be offered.