NT (Nuchal Translucency) Scan
Although new techniques for prenatal screening and diagnosis are being studied every day, the NT has stood the test of time - Mathew Leonardi MD PhD - Surgeon/Sonologist
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Nuchal Translucency: What Does It Mean?
The ultrasound test for fetal NT has been around for a long time. However, research is still being done to evaluate its utility, particularly against other screening methods, as research from the journal Prenatal Diagnosis reports. Although exciting alternatives are being developed, NT still has significant value. One study published in the American Journal of Obstetrics and Gynecology decided to challenge the approach of capturing the NT on ultrasound, evaluating the transverse view of the NT, rather than the classic sagittal view. Interestingly, the authors found that if the scan was performed by an expert sonologist, there was only a minimal difference in NT measurement between the two planes,…Featured
The Associations of Nuchal Translucency and Fetal Abnormalities; Significance and Implications
Evaluation of the nuchal translucency should be considered during the first trimester ultrasound and a detailed anatomic evaluation should be offered whenever feasible. Increased NT is associated with a spectrum of fetal abnormalities. The commonest association is with chromosomal defects. In fetuses with increased NT and a normal karyotype, the risk of an adverse outcome remains and increases with increasing NT. An NT of 3.5 mm or more should be considered significant and warrants further investigations by serum markers, depending upon the gestational age.
Articles of Interest
Nuchal translucency scan
Screening by NT can detect about 80% of fetuses with trisomy 21 and other major aneuploides for a false positive rate of 5%. The combination of NT and maternal serum free β-hCG and PAPP-A improves the detection to 90%. There is now evidence that the detection rate can increase to about 95% and the false positive rate can be reduced to 3% by also examining the nasal bone, ductus venosus flow and tricuspid flow.
Nuchal Translucency – First Trimester Measurement
A precise measurement of this space is used in first trimester aneuploidy screening in combination with levels of maternal serum markers [free or total hCG and pregnancy-associated plasma protein A (PAPP-A)] to provide an adjusted risk for fetal aneuploidy
Understanding the NT Scan in Pregnancy: What You Need to Know
The NT scan in pregnancy is an important screening test performed during the first trimester to assess the risk of chromosomal abnormalities in the developing baby. Also known as the nuchal translucency scan, this non-invasive ultrasound measures the thickness of the fluid-filled space at the back of the baby’s neck. An increased nuchal translucency measurement may indicate a higher risk of conditions like Down syndrome, Edwards syndrome, or other genetic disorders. While the NT scan does not provide a definitive diagnosis, it helps doctors determine if diagnostic testing like chorionic villus sampling (CVS) or amniocentesis is needed. Understanding this test can help expectant parents make informed decisions about their pregnancy.
What is Nuchal Translucency scan
The nuchal translucency ultrasound measures the fluid build-up behind the fetus' neck, known as the nuchal fold. If more than the normal amount of fluid is measured, it indicates genetic or structural issues in the baby, including conditions like Down's Syndrome or Trisomy 21.
Resources
Radiopaedia
Nuchal translucency is the normal fluid-filled subcutaneous space identified at the back of the fetal neck during the late first trimester and early second trimester (11 weeks 3 days to 13 weeks 6 days). It should not be confused with the nuchal fold, which is seen in the second trimester.
