Objectives

The aim of our prospective study was to assess the ability of different parameters to identify fetuses requiring neonatal care for coarctation of the aorta (CoA).

Methods

Between January 2003 and December 2012, 175 fetuses of our region referred for great vessel disproportion (pulmonary valve/aortic valve (AoV) diameter ratio ≥ 1.6) were divided into two groups: group A ( n = 51) with high risk of CoA and delivery planned in tertiary care referral center; group B ( n = 124) with no increased risk of CoA. Fetuses with Z-score aortic valve AoV < −2 at 36 weeks of amenorrhea (WA) (measurements of AoV were normalized to femoral length with Schneider’s Z-score equation) or with hypoplastic and/or angular aortic arches were considered at high risk of CoA and therefore in group A. Fetuses with at least 2 minor criteria: diagnosis before 28 WA, Z-score AoV < −1.2, ventricular septal defect and bicuspid AoV were also included in group A. Persistent left superior vena cava (LSVC) was not considered high risk, but was reported. All neonates in the 2 groups had completed postnatal follow-up with echocardiography.

Results

In group A, diagnosis of CoA was confirmed in 38/51 (75%) and isolated CoA in 22/34 (65%). In group B, 2/124 had CoA (false negative rate 1.6%). In univariate analysis, except for the LSVC, all parameters were significant ( P < 0.001) but had, if isolated, poor specificity. With our criteria, the positive predictive value was 75% when vessels disproportion was noted before 28 WA and 78% in the third trimester. 51% of all CoA had not been referred and was diagnosed after birth.

Conclusion

The results of our prospective study are in agreement with those of previous series but our false positive rate is lower and not influenced by gestational age. The performance of fetal cardiac screening does not seem to be very good but prenatal diagnosis is probably not always possible: our 2 false negative cases had vascular disproportion without any other risk factors.