ANTENATAL DIAGNOSIS OF COARCTATION OF THE AORTA - A MULTICENTER EXPERIENCE

Objectives. The purpose of this study was to test observations that might aid prenatal prediction of the presence of coarctation of the aorta in newborn infants with and without other forms of heart disease. Background. Previous reports have suggested that abnormal growth of the aortic arch in utero may be identifiable as a marker for the diagnosis of coarctation. Methods. We reviewed the prenatal echocardiograms and postnatal outcome of 20 infants (gestational age at initial study 18 to 36 weeks) with coarctation of the aorta established postnatally, to identify echocardiographic findings that would most facilitate the prenatal diagnosis of coarctation. Associated cardiac lesions included double inlet left ventricle anatomy (n = 5), double-outlet right ventricle (n = 4), abnormal aortic valve (n = 5), unbalanced atrioventricular canal.(n = 3), and membranous ventricular septal defect (n = 1). Chromosomal abnormalities included XO karyotype (n = 1), trisomy 18 (n = 1), and trisomy 21 (n = 1). Results. Hypoplasia determined by measurement of the distal aortic arch was the most frequently observed finding among the fetuses with coarctation. In 12 of 15 fetuses with a well visualized transverse arch at initial prenatal study, the diameter of the transverse arch was less than or equal to 3rd percentile for gestational age as com pared with that in a normal group of fetuses. Ten of 10 fetuses with adequate images of the isthmus had isthmus hypoplasia at prenatal study with a diameter less than or equal to 3rd percentile for gestational age. On serial study in six of seven, including three fetuses with normal distal arch measurements at initial study, the distal arch became progressively more hypoplastic for gestational age. In three there was no growth of the transverse arch or isthmus on serial study, and in three there was reversal of flow from antegrade to retrograde through the distal arch. Conclusions. In our study, quantitative hypoplasia of the isthmus and transverse arch was the most consistent observation and therefore the most definitive antenatal sign of postnatal coarctation. The potential for progression of distal arch hypoplasia necessitates serial study in fetuses with associated cardiac and noncardiac lesions.