nuchal translucency
Also written as: NT — nuchal translucency
A sonographic measurement of fluid accumulation behind the fetal neck used in first-trimester screening for chromosomal abnormalities.
Full Definition
Nuchal translucency (NT) is an ultrasound measurement taken between 11 and 14 weeks of pregnancy that assesses the clear space behind the developing baby's neck. Increased NT measurements are associated with higher risk of chromosomal abnormalities, particularly Down syndrome, as well as certain structural defects and genetic syndromes. NT measurement is a key component of combined first-trimester screening protocols and must be performed by certified sonographers using standardized techniques to ensure accuracy.
Usage
Usage note: Commonly abbreviated as NT in medical records.
In Context
- "The nuchal translucency measured 3.2 mm, prompting referral for genetic counseling." — Ultrasound report
- "Combined screening incorporating nuchal translucency and biochemical markers detected 85% of Down syndrome cases." — Clinical guideline