Prenatal diagnosis of tricuspid atresia with hypoplastic right ventricle associated with truncus arteriosus communis type II.

PURPOSE: To confirm the central role of antenatal echocardiography and necropsy in the prenatal diagnosis of rare congenital heart defects. METHODS: A 33-year-old woman undergoing second trimester scan using 2D transabdominal and Doppler sonography. RESULTS: The echocardiographic examination showed, at the level of the four-chamber view, a predominant left ventricle with a rudimental right ventricle and a single artery emerging with failed visualization of the pulmonary trunk: a diagnosis of truncus arteriosus communis associated with tricuspid atresia and hypoplastic right heart was made. No other ultrasound-associated anomalies were seen. Fetal karyotype and 22q11.2 microdeletion for Di George syndrome were sought using cordocentesis performed at 21 weeks and both the results were normal. After extensive counselling, the couple opted for termination of pregnancy at 22 weeks gestation. Necroscopy confirmed the prenatal ultrasound diagnosis. Necroscopy of the heart was performed in a manner that resembled the fetal echocardiographic examination and revealed two atria, two atrio-ventricular valves with recognizable mitral and tricuspid morphology, a prevalent ventricle of left-type and a rudimental ventricle of right type and a ventricular septal defect. The common truncus was seen coming out above the ventricular septum, whilst the pulmonary arteries arise separated from the truncus communis. No other structural thoraco-abdominal anomalies were found. CONCLUSIONS: A combined diagnostic strategy based on second trimester fetal echocardiography, genetic analysis and necroscopy has made identification of a rare congenital heart disease possible.