Use of fetal nuchal translucency in the first trimester to predict single-gene disorders

Abstract

Objective: To assess the predictive value of fetal nuchal translucency (NT) measurement in the prenatal diagnosis of single-gene disorders. Methods: From January 1996 to December 2006, fetal NT was prospectively measured before chorionic villi sampling in 169 pregnancies at high risk for a single-gene disorder at 11 to 13 weeks of pregnancy. Results: No differences were found between the 63 affected and 116 nonaffected fetuses in pregnancy demographic characteristics, in mean NT measurements, expressed either in millimetres [1.8 (95% CI:1.6-1.9) vs 1.7 (95% CI:1.6-1.8)] or in multiples of the median [1.19 (95%CI: 1.04-1.35) vs 1.14 (95%CI: 1.05-1.23)], or in median NT. The percentage of increased NT above the 95 th percentile was similar for affected (9.5%) and nonaffected (11.2%) fetuses. Conclusion: Not all single-gene disorders are associated with enlarged NT, therefore NT cannot be regarded as a generic marker for single-gene disorder but only for a limitednumber of these conditions. © 2011 John Wiley & Sons, Ltd.