Normal pregnancy and antenatal care: drugs in pregnancy: 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.

Try it

OBG · Normal pregnancy and antenatal care: drugs in pregnancy

Sample item

A woman at 24 weeks on enalapril for chronic kidney disease has a scan showing oligohydramnios with small echogenic kidneys in the fetus. Which mechanism explains this?

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

The answer and the reasoning

A. Fall in fetal glomerular filtration from angiotensin converting enzyme inhibition

ACE inhibitors and angiotensin receptor blockers impair fetal renal perfusion and function in the second and third trimesters, reducing urine and so amniotic fluid. They are replaced before or early in pregnancy by labetalol, nifedipine or methyldopa.

Option by option

  • A. Fall in fetal glomerular filtration from angiotensin converting enzyme inhibition (correct)

    Correct. Reduced fetal glomerular filtration lowers urine output and fluid volume.

  • B. Placental infarction caused by the drug

    Infarction is not the recognised mechanism of this fetopathy.

  • C. Fetal ureteric obstruction from the drug

    The drug does not cause ureteric obstruction.

  • D. Direct damage to fetal lung epithelium

    Lung epithelium is not the target; the fluid loss follows renal failure.

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 A, Fall in fetal glomerular filtration from angiotensin converting enzyme inhibition. ACE inhibitors and angiotensin receptor blockers impair fetal renal perfusion and function in the second and third trimesters, reducing urine and so amniotic fluid.

Why is "Placental infarction caused by the drug" not the answer?

Infarction is not the recognised mechanism of this fetopathy.

Why is "Fetal ureteric obstruction from the drug" not the answer?

The drug does not cause ureteric obstruction.

Why is "Direct damage to fetal lung epithelium" not the answer?

Lung epithelium is not the target; the fluid loss follows renal failure.

What concept does this question test?

It tests Normal pregnancy and antenatal care: drugs in pregnancy in OBG. They are replaced before or early in pregnancy by labetalol, nifedipine or methyldopa.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. 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 Normal pregnancy and antenatal care: drugs in pregnancy?

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.