Neonatology: neonatal lupus and heart block: practice question

A Pediatrics 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.

Try it

Pediatrics · Neonatology: neonatal lupus and heart block

Sample item

Routine antenatal scanning at 24 weeks shows a fetal heart rate of 55 per minute with no structural heart defect. The mother has Sjogren syndrome. Which maternal antibody is most likely responsible?

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

The answer and the reasoning

A. Anti-Ro (SSA) antibody

Maternal anti-Ro/SSA (and anti-La/SSB) IgG crosses the placenta and damages the fetal AV node, causing congenital complete heart block in a structurally normal heart. Neonatal lupus may also cause a transient photosensitive rash and cytopenias. The mother may be asymptomatic or have Sjogren syndrome or lupus.

Option by option

  • A. Anti-Ro (SSA) antibody (correct)

    Correct. Anti-Ro/SSA crosses the placenta and injures the fetal conduction tissue.

  • B. Anti-Smith antibody

    Anti-Smith is specific for lupus but is not linked to fetal conduction block.

  • C. Anti-centromere antibody

    Anti-centromere antibody is associated with limited systemic sclerosis.

  • D. Anti-double stranded DNA antibody

    Anti-dsDNA relates to lupus nephritis activity and is not the cause of fetal heart block.

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 Pediatrics questions

Questions about this Pediatrics question

What is the answer to this Pediatrics question?

The best answer is A, Anti-Ro (SSA) antibody. Maternal anti-Ro/SSA (and anti-La/SSB) IgG crosses the placenta and damages the fetal AV node, causing congenital complete heart block in a structurally normal heart.

Why is "Anti-Smith antibody" not the answer?

Anti-Smith is specific for lupus but is not linked to fetal conduction block.

Why is "Anti-centromere antibody" not the answer?

Anti-centromere antibody is associated with limited systemic sclerosis.

Why is "Anti-double stranded DNA antibody" not the answer?

Anti-dsDNA relates to lupus nephritis activity and is not the cause of fetal heart block.

What concept does this question test?

It tests Neonatology: neonatal lupus and heart block in Pediatrics. Neonatal lupus may also cause a transient photosensitive rash and cytopenias. The mother may be asymptomatic or have Sjogren syndrome or lupus.

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 Neonatology: neonatal lupus and heart block?

Memorise milestones and the vaccine schedule as tables and revise them often. Then use the flashcards and the other Pediatrics 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.