Diagnostic Yield of Chromosomal Microarray Analysis in Fetuses with Isolated Increased Nuchal Translucency: A French Multicenter Study

(Abstracted from Ultrasound Obstet Gynecol 2018;52:715–721) Nuchal translucency (NT) is a collection of fluid at the back of the fetal neck; its thickness can be measured by ultrasound between 10 and 13 + 6 weeks of gestation. An increased thickness, often defined as an NT of greater than the 99th centile, which corresponds approximately to a threshold of 3.5 mm, is associated with a risk of chromosomal abnormalities, as well as genetic syndromes such as Noonan and Smith-Lemli-Opitz syndrome, and major structural birth defects.