Utility of novel echocardiographic measurements to improve prenatal diagnosis of coarctation of the aorta

Objective: Prenatal recognition of coarctation of the aorta (CoA) may improve neonatal survival and reduce morbidity. However, prenatal diagnosis of CoA remains challenging, with relatively high false–positive and false–negative rates. This study aimed to identify a novel formula based on fetal echocardiographic measures to predict prenatal identification of CoA. Methods A retrospective comparison on the echocardiographic evaluation of 30 patients with suspected CoA between May 2016 and April 2021 was performed. Fetal echocardiograms were measured for the following: Z-score of right and left ventricular diameters, tricuspid and mitral valve diameters, pulmonary artery and ascending aorta diameters, pulmonary valve and aortic valve diameters, ductus arteriosus and aortic isthmus diameters and their respective ratios, and distal aortic arch (DA) index, which is the distance between the second and third branches of the aortic arch / distal aortic arch diameter. The patients were divided into a postnatal surgical intervention group (n = 13) and a non-intervention group (n = 17). Results The measurements that showed significant differences were aortic isthmus diameter Z-score (p < 0.001), ductus arteriosus diameter/aortic isthmus diameter (p < 0.001) and DA index (p < 0.001). In the receiver operating characteristic curves analysis, the DA index was the largest with an area under the curve of 0.941 and a cutoff value of 1.28, with a sensitivity of 85% and a specificity of 94%. Among the three parameters that showed significant differences, the DA index had the lowest false-positive rate (5.9%). Conclusions The DA index ≧ 1.28 allows for the extraction of fetal CoA cases requiring surgical intervention.