RESUMO
INTRODUCTION: During the last decades, a major achievement was reported in detecting Down's syndrome in the first trimester of pregnancy. This is attributed to the use of high-resolution accurate ultrasound machine allowing the detection of a "nuchal translucency" in the back of the fetus during 11-14 weeks' gestation. This is considered to be a physiologic finding, but when increased, may alert for chromosomal abnormality (mainly Down's syndrome), cardiac and other organ anomalies and other genetic syndromes. Later additional sonographic findings were found, including nasal bone assessment, and Doppler flow studies of the ductus venosus and tricuspid regurgitation Technology advancement accompanied by sonographers' skills enhancement allows (at the time frame of the nuchal scan) a detailed anomaly scan. Additional screening for pregnancy complication was achieved using first trimester multi marker assessment, alerting for preeclamptic toxemia or placenta accreta. Currently, many national and international professional organizations recommend performing the nuchal scan concurrent with an early anomaly scan both at the same time of gestation. This approach is different than the one performed in Israel, whereas the nuchal scan is conducted separately and 2-3 weeks later an anomaly scan is offered. We call for reconsideration of the sequential approach and performing all the tests in a comprehensive first trimester clinic.