From the Research
Nuchal Translucency Measurement
- A nuchal translucency (NT) of 1.2 mm is considered normal, as most studies define abnormal NT as ≥ 2.5 mm or ≥ 3 mm 1, 2.
- However, a case study reported a fetus with an NT of 1.2 mm at 13 weeks' gestation, which was later diagnosed with hypoplastic left heart syndrome and trisomy 18 3.
- This suggests that even with a normal NT measurement, there is still a possibility of congenital anomalies or chromosomal abnormalities.
Association with Congenital Anomalies
- Increased NT is associated with various fetal defects, including cardiac, chromosomal, and other defects 2.
- Cardiac diseases associated with increased NT include heart murmur, systolic organic murmur, Atrial Septal Defect (ASD), Ventricular Septal Defect (VSD), and others 2.
- Abnormal ductus venosus blood flow at 13 weeks of gestation may be an early sign of congenital cardiac or chromosomal abnormality, even in the presence of normal NT screening 3.
Pathophysiology of Increased NT
- The aetiology of increased NT is still not fully understood, but several hypotheses have been proposed, including cardiac failure, abnormalities in the extracellular matrix of the nuchal skin, and abnormal lymphatic development 4.
- These hypotheses are based on associations and speculations, and further research is needed to fully understand the pathophysiology of increased NT 4.