Evaluating the Performance of Ultrasound Screening for Congenital Heart Disease: A Descriptive Cohort Study

Objective The objective of this study was to evaluate the rate of abnormal fetal echocardiogram after normal detailed anatomy ultrasound when both are performed by maternal-fetal medicine specialists. Study Design Retrospective review of women who underwent detailed anatomy ultrasound and fetal echocardiography between 16 and 26 weeks' gestation at a single center. Women included had at least one indication for fetal echocardiography as recommended by the American Institute of Ultrasound in Medicine and normal cardiac anatomy on initial detailed anatomy ultrasound. Women with previous abnormal ultrasound, extracardiac anomalies, and abnormal or incomplete cardiac anatomy on initial examinations were excluded. The primary outcome was abnormal fetal echocardiogram, defined as a structural cardiac anomaly. Results A total of 1,000 women (1,052 fetuses) were included. The most common indication for echocardiography was family history of congenital heart disease. Five fetuses had an abnormal echocardiogram (0.5%, 95% confidence interval: 0.2-1.1%), only one of which altered care. The other four were suspected ventricular septal defects; of these, three were not seen on postnatal cardiac imaging. Conclusion The rate of abnormal fetal echocardiogram after a normal detailed anatomy ultrasound interpreted by maternal-fetal medicine specialists is low. Fetal echocardiography as a second screening test is of low clinical utility and unlikely to be cost-effective in this setting.