Evaluating the Diagnostic Significance of Major Cardiac Anomalies via First Trimester Ultrasound and Their Association with Elevated Nuchal Translucency, Tricuspid Regurgitation, and Irregular Ductus Venosus Flow

Background: Congenital heart defects (CHDs) are a major cause of death and illness in newborns. Early detection is vital for prompt treatment and better outcomes. This study explored the effectiveness of first-trimester ultrasound in identifying CHDs and its association with increased nuchal translucency (NT), tricuspid regurgitation (TR), and abnormal ductus venosus (DV) flow. Methods: This cross-sectional study involved all pregnant women who had first-trimester screening ultrasounds performed by an obstetrician or radiologist at Forghani Hospital between 2017 and 2024. These women were subsequently referred for fetal echocardiography at 16-18 weeks of gestation at Hazrat Masoumeh Hospital in Qom, Iran. Postnatal neonatal echocardiography was conducted for all cases. The study calculated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of increased nuchal translucency (NT), tricuspid regurgitation (TR), and abnormal ductus venosus (DV) flow in detecting congenital heart defects (CHDs). Results: The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of increased nuchal translucency (NT) for detecting congenital heart defects (CHDs) were 74.7%, 98.3%, 90.9%, and 94.7%, respectively. For tricuspid regurgitation (TR), these values were 71.9%, 97.7%, 87.5%, and 94.1%, respectively. Regarding abnormal ductus venosus (DV) flow, the values were 82.2%, 95.1%, 78.5%, and 96.1%, respectively. The diagnostic accuracy for detecting CHDs using NT, TR, and abnormal DV flow was 94.1%, 93.1%, and 92.8%, respectively. Conclusion: Targeted fetal ultrasound in the first trimester is a valuable diagnostic tool for detecting CHDs. Early detection can contribute to improved neonatal outcomes.