Congenitally Corrected Transposition of the Great Arteries in Utero: Morphological Spectrum, Outcomes and Pitfalls in Fetal Diagnosis

Abstract

Congenitally corrected transposition of the great arteries (ccTGA) is a rare malformation with diverse morphology. We assessed features of fetuses with ccTGA and evaluated neonatal and pediatric outcomes. This was a retrospective review of fetuses with ccTGA at Birmingham Women's and Children's Hospital born from 2005 to 2019. Of thirty-six fetuses identified, six had unavailable prenatal data, one was postnatally diagnosed with isomerism and 29 fetuses were evaluated. ccTGA without associated cardiac lesions was found in 28% (8/29), ccTGA with significant VSD in 31% (9/29), ccTGA with pulmonary obstruction in 24% (7/29) and ccTGA with complex anomalies in 17% (5/29). Tricuspid regurgitation (TR) was observed in 17% (5/29) and heart block (HB) in 10% (3/29) prenatally. Six, that is 21% underwent genetic testing of which one was abnormal. Five extra-cardiac anomalies were reported prenatally and postnatally. Pregnancy was discontinued in five, of which two had moderate TR. There were thirty-one liveborn. Coarctation of the aorta was found in five postnatally but not suspected prenatally. In one, pulmonary stenosis was underestimated; otherwise, prenatal morphology was confirmed. Cardiac interventions were performed in 77% (24/31) liveborn with 39% (12/31) undergoing neonatal intervention. Overall, 6/31 liveborn died including all three with prenatal heart block and one with TR. Estimated survival for all liveborn at 1, 5 and 10 years was 87% (95% CI 76-100%), 83% (95% CI 72-98%) and 80% (95% CI 66-96%) respectively. Accurate prenatal diagnosis of ccTGA is critical for counseling. Early outcomes are favorable with 77% of liveborn undergoing surgery. Fetuses with prenatal diagnosis of complex associated abnormalities, HB and TR appear to do less well.

Keywords: Congenitally Corrected Transposition of the Great Arteries, Morphology, Fetal.