Measurement of nuchal translucency for prenatal screening of congenital heart defects: a population-based evaluation.

OBJECTIVES

(1) Assess sensitivity of the measurement of nuchal translucency (NT), for the prenatal screening of congenital heart defect (CHD) on population-based data; (2) examine whether the sensitivity of NT varies for specific types of cardiac defects.

METHODS

Using population-based data of the Paris Registry of Congenital Malformation for 935 fetuses with CHD and without chromosomal anomalies for the period 2001 to 2007, we calculated sensitivity of NT, its positive predictive value and likelihood ratio, for all CHD and for six types of CHD.

RESULTS

Sensitivity of NT was 7.1 and 4.2% for the 2.5 and 3.5 mm cut-off values, respectively; when isolated ventricular septal defects were excluded, sensitivity increased to 9.9 and 6.3%. Positive predictive values were 1.1 and 3.2% for 2.5 and 3.5 mm cut-offs, respectively. Of the six defects examined, sensitivity of NT was highest for heterotaxy followed by hypoplastic left heart syndrome and coarctation of aorta.

CONCLUSION

Prevalence of CHD was about fourfold higher for fetuses with NT ≥ 3.5 mm (3.2%) than in the general population. This higher risk is comparable to that of other risk factors commonly used for early referral to specialized echocardiography. Nevertheless, our results, suggest that NT is not a very effective or efficient tool for the prenatal screening of CHD.