Obstetric imaging: nuchal translucency: practice question

A Radiology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Radiology · Obstetric imaging: nuchal translucency

Sample item

A first-trimester screening ultrasound measures nuchal translucency. At what gestational age is it measured and what does an increased value suggest?

A18 to 20 weeks; neural tube defectB28 weeks; growth restrictionC6 weeks; ectopic pregnancyD11 to 13 weeks and 6 days; chromosomal anomalies such as Down syndrome

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

D. 11 to 13 weeks and 6 days; chromosomal anomalies such as Down syndrome

Nuchal translucency is measured when the crown-rump length is 45 to 84 mm, and an increased thickness (above 3 mm or above 95th centile) is associated with trisomies 21, 18 and 13, cardiac defects and other anomalies. Combined screening with free beta hCG and PAPP-A improves detection. Neural tube defects are screened at the second trimester anomaly scan.

Option by option

A. 18 to 20 weeks; neural tube defect
At 18 to 20 weeks the anomaly scan screens for structural defects.
B. 28 weeks; growth restriction
At 28 weeks, growth is assessed.
C. 6 weeks; ectopic pregnancy
At 6 weeks the NT cannot be measured.
D. 11 to 13 weeks and 6 days; chromosomal anomalies such as Down syndrome (correct)
Correct. NT at 11 to 13 weeks and 6 days screens for aneuploidy.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this Radiology question

What is the answer to this Radiology question?

The best answer is D, 11 to 13 weeks and 6 days; chromosomal anomalies such as Down syndrome. Nuchal translucency is measured when the crown-rump length is 45 to 84 mm, and an increased thickness (above 3 mm or above 95th centile) is associated with trisomies 21, 18 and 13, cardiac defects and other anomalies.

Why is "18 to 20 weeks; neural tube defect" not the answer?

At 18 to 20 weeks the anomaly scan screens for structural defects.

Why is "28 weeks; growth restriction" not the answer?

At 28 weeks, growth is assessed.

Why is "6 weeks; ectopic pregnancy" not the answer?

At 6 weeks the NT cannot be measured.

What concept does this question test?

It tests Obstetric imaging: nuchal translucency in Radiology. Combined screening with free beta hCG and PAPP-A improves detection. Neural tube defects are screened at the second trimester anomaly scan.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Obstetric imaging: nuchal translucency?

Learn signs with the image, and the disease they point to. Then use the flashcards and the other Radiology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.