Prenatal Diagnosis of Congenital Cardiac Anomalies: A Practical Approach Using Two Basic Views

Abstract

Structural cardiac anomalies are estimated to occur in 8 of every 1,000 live births. Cardiovascular anomalies are frequently associated with other congenital anomalies because the heart is among the last organs to develop completely in the embryo. The guidelines for routine prenatal evaluation of both the American College of Radiology and the American Institute of Ultrasound in Medicine require evaluation of the fetal heart. The ultrasonographic (US) view that is most commonly used is the four-chamber view, which allows assessment of abnormalities involving the atria and the ventricles. However, this view is not adequate for demonstrating the outflow tracts of the aorta and pulmonary artery. A base view that demonstrates the crossing of the great vessels can be obtained just superior to the four-chamber view. Addition of the base view to routine US evaluation with the four-chamber view increases not only the sensitivity for detection of cardiac anomalies but also the accuracy of diagnosis.

Fetal cardiac circulation in isolated aortic atresia assessed with ultrasound

“…They detected a small left ventricular cavity and hypoplastic aortic arch in the first fetus and no ventricular cavity and a bright ecogenity in its place in the second fetus. The gestation was terminated at 17 weeks, hypoplastic left heart syndrome was verified and mitral and aortic atresia were detected at autopsy (7,8). In this case, because mitral valve failure developed with aortic atresia, mild dilatation of the left ventricle, diffuse cardiomegaly, and a mild left deviation of the interventricular septum were seen.…”

Accuracy of the Fetal Echocardiography in the High Risk Pregnancies

“…[3][4][5][6]9 The questions which have been raised from the early years of development of fetal echocardiography for detection of CHD, were:…”

“…[3][4][5][6][23][24][25] The screening method is relatively simple and cost effective, while the intervention after the screening could be effective. Fetal echocardiography has been a useful tool either for the prenatal detection of CHD or for the detection of other heart lesions as arrhythmias or cardiomyopathies.…”

“…Fetal echocardiography has been a useful tool either for the prenatal detection of CHD or for the detection of other heart lesions as arrhythmias or cardiomyopathies. [3][4][5][6]9,[23][24][25] Most cases of CHD occur in otherwise normal pregnancies, although the risk of CHD is markedly increased in aneuploidies. 6,11,20,26 It was revealed in the 1980s that fetal echocardiography could predict correctly structural malformations of the heart with the conclusion that the technique is sufficiently reliable to give an accurate prognosis in early pregnancy and provide the basis for alterations in obstetric management.…”

“…The incidence of CHD is estimated to be 0.8 in 1000 liveborn infants, and therefore this new possibility to diagnose them prenatally, has also important public-health implications. [3][4][5] Another question, raised but so far not solved during the development of fetal echocardiography, was that screening of CHD is necessary for all, not only for high-risk pregnancies. 6 Very important criterion for the screening method is its simplicity, good sensitivity and specificity, acceptable reliability and low costs.…”