Conotruncal Anomalies of the Fetus

Approximately 0.8 % of all children are born with heart defects, with the prenatal incidence naturally being even higher. Among all congenital heart defects (CHD), conotruncal anomalies are the most common critical heart defects - after ventricular and atrial septal defects. Conotruncal anomalies are anomalies of the infundibulum (conus arteriosus) and great vessels (truncus arteriosus). These anomalies predominantly affect the right ventricular outflow tract and account for about 25-30 % of all CHD cases. Based on their incidence and clinical relevance, this article describes perimembranous ventricular septal defects (VSD), tetralogy of Fallot (TOF), pulmonary atresia with VSD (PAVSD), transposition of the great arteries (TGA), and the less common double outlet right ventricle (DORV) and truncus arteriosus communis (TAC).Conotruncal anomalies are usually associated with a normal 4-chamber view, so the prenatal detection rate during prenatal care tends to be low. However, because undetected conotruncal anomalies have high rates of postnatal mortality and morbidity, in accordance with internationally recommended policies, the foetal heart should always be examined systematically and segmentally in different sectional planes, including the outflow tract and in combination with the color Doppler, to achieve a higher detection rate. This article provides an overview of prenatal sonographic diagnosis of conotruncal anomalies based on extensive imaging material.