Question

Increased nuchal translucency at 14 weeks gestation is seen in:

• A. Turner's syndrome
• B. Down's syndrome
• C. Hydrocephalus
• D. Skeletal dysplasia

Hint:

Increased nuchal translucency is the classic first-trimester marker of trisomy 21.

Answer 1

The Correct Option is B

Step 1: Nuchal translucency (NT) is the sonographic measurement of the fluid collection at the back of the fetal neck, taken between 11 and 14 weeks. An increased NT is a marker of chromosomal and structural abnormality.
Step 2: Increased NT is most strongly and most commonly linked with Down's syndrome (trisomy 21), where it forms part of the combined first-trimester screen along with maternal age, free beta-hCG and PAPP-A.
Step 3: Turner's syndrome (45,X) can also raise NT, but in Turner's the classic finding is a cystic hygroma and a much larger nuchal collection rather than the modest NT increase, and it is not the single best answer the examiner wants here.
Step 4: Hydrocephalus and skeletal dysplasia are not first-trimester NT markers in the way trisomy 21 is; they present later with their own specific findings.
Step 5: Because Down's syndrome is the classic and most examined association of increased NT, the answer is Down's syndrome.
Hence the answer is Down's syndrome, option B.