The genetic sonogram today: What is the role of "soft markers" in the prediction of down syndrome?

Background: The aim of this study is to evaluate the role of "soft markers" in the prediction of Down syndrome (DS). Methods: This study includes an unselected population of 1999 pregnant women who requested a fetal karyotype test using amniocentesis at gestational ages ranging from 15 to 20 weeks. Before performing the amniocentesis, an ultrasound examination was conducted to detect the presence of a series of fetal "soft markers." Results: We identified 148 fetuses affected by DS and 1795 euploid fetuses (control group). The marker found to have the most significant likelihoodratio (LR) was increased nuchal fold. The marker found to have the greatest sensitivity was echogenic intracardiac focus. The other soft markers (as single markers) were not significant. Conclusions: An ultrasound scan cannot diagnose or rule out DS. However, it can be a useful method for modifying the baseline "a priori" probability of DS in any particular patient.