Minnella GP, et al. - Researchers investigated a large population of singleton pregnancies undergoing a routine ultrasound examination at 11-13 weeks' gestation for the correlation between fetal major heart defects and high nuchal translucency thickness (NT), tricuspid regurgitation and abnormal flow in the ductus venosus. At 11-13 weeks' gestation measurement of fetal NT and assessment of flow across the tricuspid valve and in the ductus venosus can lead to the early diagnosis of major heart defects. In this retrospective study, 93,209 pregnancies with no apparent chromosomal abnormality were included; of these, 211 (0.23%) neonates had major heart defects and 92,998 neonates were morphologically normal. Scan at the 11-13 weeks led to the diagnosis of all cases of tricuspid or pulmonary atresia and polyvalvular dysplasia, > 90% of cases of hypoplastic left heart syndrome or atrioventricular septal defect, about 60% of complex heart defects and left atrial isomerism (interrupted inferior vena cava with normal intracardiac anatomy), 30-40% of tetralogy of Fallot and arch abnormalities, 25% of tricuspid valve abnormalities, about 15% of transposition of great arteries, but none of aortic or pulmonary stenosis and common arterial trunk. Findings support the utility of measuring fetal NT and assessing flow across the tricuspid valve and in the ductus venosus at 11-13 weeks' gestation for the early diagnosis of major heart defects.