When is the optimal time to perform fetal nuchal translucency (NT) screening?

The fetal nuchal translucency (NT) scan is ideally performed between 12 and 14 weeks of gestation. During embryonic development, the nuchal translucency—the fluid-filled space at the back of the fetal neck—becomes optimally visible during this period, allowing for effective detection of chromosomal abnormalities and other conditions. Performing the NT scan too early (before 12 weeks) is not advisable, as the nuchal translucency has not yet fully developed and thus cannot serve as a reliable marker for first-trimester screening. Similarly, scanning beyond 14 weeks diminishes its diagnostic accuracy and clinical utility.