Increased nuchal translucency and congenital heart defects in a low-risk population

Abstract

Objective: Increased first-trimester nuchal translucency (NT) is a possible marker for congenital heart defects in euploid fetuses. In this study, we wanted to determine the sensitivity for congenital heart defects using the 95th centile of the NT as a cut-off point.

Methods: All women who booked for delivery in our hospital in the first trimester underwent NT measurement at a crown-rump length (CRL) of between 35 and 75 mm. In all euploid fetuses and newborns with isolated or associated CHD, NT was examined retrospectively and classified as normal (<95th centile according to CRL-dependent centiles in our own data) or increased (> or =95th centile).

Results: From a total of 12,978 euploid fetuses screened, 27 had CHD (22 isolated and 5 cases associated with additional malformations). Moreover, 7 of the 27 fetuses also had increased NT (26%). Increased NT was significantly more frequent in fetuses with associated CHD (4/5) than in those with isolated CHD (3/22, Yates corrected chi2 p=0.012). In fact, the relative risk for CHD was 6.6 times higher in fetuses with increased NT compared to those with normal NT.

Conclusion: Increased NT for the detection of CHD performed less well than in other studies. Nevertheless, it can be used as an indication for fetal echocardiography.