Antenatal care: first trimester screening: practice question

A OBG 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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OBG · Antenatal care: first trimester screening

Sample item

A 38-year-old woman at 12 weeks has a nuchal translucency of 4.2 mm. Which additional biochemical finding would support trisomy 21?

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

The answer and the reasoning

D. Low PAPP-A and high free beta hCG

Combined first-trimester screening uses nuchal translucency measured at 11 to 13+6 weeks together with PAPP-A and free beta hCG. In Down syndrome PAPP-A is low and free beta hCG is high. A positive screen is followed by cell-free DNA or invasive testing.

Option by option

  • A. High PAPP-A and low free beta hCG

    This is the reverse of the expected pattern.

  • B. Normal PAPP-A with low inhibin A

    Inhibin A is a second-trimester marker, and normal PAPP-A would not support aneuploidy.

  • C. Low PAPP-A and low free beta hCG with high AFP

    AFP is not part of first-trimester combined screening.

  • D. Low PAPP-A and high free beta hCG (correct)

    Correct. Low PAPP-A with raised free beta hCG is the Down syndrome pattern.

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.

More OBG questions

Questions about this OBG question

What is the answer to this OBG question?

The best answer is D, Low PAPP-A and high free beta hCG. Combined first-trimester screening uses nuchal translucency measured at 11 to 13+6 weeks together with PAPP-A and free beta hCG.

Why is "High PAPP-A and low free beta hCG" not the answer?

This is the reverse of the expected pattern.

Why is "Normal PAPP-A with low inhibin A" not the answer?

Inhibin A is a second-trimester marker, and normal PAPP-A would not support aneuploidy.

Why is "Low PAPP-A and low free beta hCG with high AFP" not the answer?

AFP is not part of first-trimester combined screening.

What concept does this question test?

It tests Antenatal care: first trimester screening in OBG. In Down syndrome PAPP-A is low and free beta hCG is high. A positive screen is followed by cell-free DNA or invasive testing.

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 Antenatal care: first trimester screening?

Learn management algorithms as steps: PPH, eclampsia, ectopic pregnancy. Then use the flashcards and the other OBG 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.