Utility of novel fetal echocardiographic morphometric measures of the aortic arch in the diagnosis of neonatal coarctation of the aorta.

OBJECTIVES: Prenatal diagnosis of neonatal coarctation of the aorta (CoA) is challenging; there is a high false-positive rate, yet 60-80% are not identified prenatally. We aimed to identify novel fetal echocardiographic measures to improve prenatal identification of CoA.

METHODS: A retrospective review was conducted of subjects seen from 1/2007-1/2014 with prenatal suspicion for CoA and postnatal follow-up. The last fetal echocardiogram prior to delivery was evaluated for right/left ventricular dimensions, ascending (AAo), transverse (TAo), descending aorta (DAo), aortic isthmus (AoI), ductus arteriosus (DA), and main pulmonary artery diameters, and AoI and DA spectral Doppler. Three novel fetal measurements were performed: left common carotid-to-left subclavian artery distance (LCSA), AAo-DAo angle, and TAo-DAo angle. Postnatal data included diagnosis, surgical approach, and timing.

RESULTS: Forty subjects were identified (mean gestational age at fetal echo 32.8 ± 4.2 weeks) with prenatal suspicion for CoA. Comparing subjects with (n = 20) and without CoA (n = 20), significant differences were detected for LCSA, AAo-DAo angle, and TAo-DAo angle (p < 0.0001). An LCSA >4.5 mm (sensitivity 80%,specificity 95%), AAo-DAo angle ≤20.31° (sensitivity 95%,specificity 100%) and TAo-DAo angle ≥96.15°(sensitivity 90%,specificity 100%) identified CoA.

CONCLUSIONS: Fetal LCSA, AAo-DAo angle, and TAo-DAo angles are novel measures that can differentiate between subjects with and without CoA.