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


CONCLUSIONS
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 limited number of these conditions.
Maternal-fetal Medicine Department, ICGON, Hospital Clinic Barcelona, Spain.
Marta
M
Arigita
Antoni
A
Borrell
Raquel
R
Mula
Aurora
A
Sanchez
Montse
M
Milà
Eduard
E
Gratacos
D000293:Adolescent; D000328:Adult; D005260:Female; D030342:Genetic Diseases, Inborn / Q000000981:diagnostic imaging*; D006801:Humans; D048208:Nuchal Translucency Measurement; D011237:Predictive Value of Tests; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D055815:Young Adult