Preterm labour: fetal fibronectin: 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 · Preterm labour: fetal fibronectin

Sample item

A woman at 30 weeks with irregular tightenings has a closed cervix of 3 cm length and a negative fetal fibronectin test. How should the result be used?

AA negative test confirms she will deliver at termBPositive predictive value is excellent, so tocolysis is neededCIt is a test of fetal lung maturityDHigh negative predictive value, so delivery within 7 to 14 days is unlikely

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

The answer and the reasoning

D. High negative predictive value, so delivery within 7 to 14 days is unlikely

Fetal fibronectin is a glycoprotein released at the choriodecidual interface, and its detection in cervicovaginal fluid between 22 and 34 weeks predicts preterm birth. Its strength is the negative predictive value above 95 percent for delivery within 1 to 2 weeks. The positive predictive value is poor.

Option by option

A. A negative test confirms she will deliver at term
It only predicts the next 1 to 2 weeks, not term delivery.
B. Positive predictive value is excellent, so tocolysis is needed
A positive result has low positive predictive value.
C. It is a test of fetal lung maturity
It does not assess lung maturity.
D. High negative predictive value, so delivery within 7 to 14 days is unlikely (correct)
Correct. A negative result reliably rules out imminent preterm delivery.

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 OBG question

What is the answer to this OBG question?

The best answer is D, High negative predictive value, so delivery within 7 to 14 days is unlikely. Fetal fibronectin is a glycoprotein released at the choriodecidual interface, and its detection in cervicovaginal fluid between 22 and 34 weeks predicts preterm birth.

Why is "A negative test confirms she will deliver at term" not the answer?

It only predicts the next 1 to 2 weeks, not term delivery.

Why is "Positive predictive value is excellent, so tocolysis is needed" not the answer?

A positive result has low positive predictive value.

Why is "It is a test of fetal lung maturity" not the answer?

It does not assess lung maturity.

What concept does this question test?

It tests Preterm labour: fetal fibronectin in OBG. Its strength is the negative predictive value above 95 percent for delivery within 1 to 2 weeks. The positive predictive value is poor.

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 Preterm labour: fetal fibronectin?

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.