Ultrasound Examination of the Fetal Heart.

Congenital heart disease (CHD) occurs in 4-13 per 1000 births in the United States. While many risk factors for CHD have been identified, more than 90% of cases occur in low-risk patients. Guidelines for fetal cardiac screening during the second trimester anatomy ultrasound have been developed by the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) in order to improve antenatal detection rates and to standardize the fetal cardiac screening examination. Patients found to be at increased risk of CHD because of risk factors or an abnormal screening examination should be referred for second trimester fetal echocardiography. Recently, 3D and 4D ultrasound techniques are being utilized to enhance detection rates and to better characterize cardiac lesions, and several first trimester ultrasound screening markers have been proposed to identify patients at increased risk of CHD. However, detection rates have not improved significantly due to limitations such as cost, access, and training that are associated with new technologies and screening methods. The most cost effective way to improve detection rates of CHD may be to standardize screening protocols across practices according to established guidelines and to have a low threshold for referral for fetal echocardiography.