Rethinking second‐trimester Down‐syndrome screening in the cell‐free DNA era

Abstract

In recent decades the focus of Down s syndrome screening using maternal serum and ultrasound markers has shifted from the second to the first trimester. This has been driven by better screening performance at 11-13 weeks gestation compared with 15-19 weeks. Moreover, first trimester screening has the clinical advantages of earlier prenatal diagnosis, and if required, a safer and less traumatic termination of pregnancy. This article is protected by copyright. All rights reserved.