Labour and delivery: placental CRH: 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 · Labour and delivery: placental CRH

Sample item

In late pregnancy, a placental peptide rises exponentially in maternal blood and is implicated in the timing of labour by stimulating fetal adrenal DHEA sulphate output and promoting myometrial contractility. Which peptide is this?

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

The answer and the reasoning

C. Placental CRH

Placental CRH rises exponentially towards term, which has been called the placental clock. It stimulates fetal adrenal DHEA sulphate (the substrate for placental oestrogen) and enhances the effect of prostaglandins on the myometrium.

Option by option

  • A. Inhibin A hormone

    Inhibin A is a screening marker in the quadruple test and does not time labour.

  • B. Relaxin hormone

    Relaxin softens the cervix and pelvic ligaments but does not follow an exponential late rise like this.

  • C. Placental CRH (correct)

    Correct. Placental CRH rises exponentially and drives fetal adrenal androgen output and oestrogen production.

  • D. Human placental lactogen

    Human placental lactogen mediates maternal metabolic adaptation and does not time labour.

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 C, Placental CRH. Placental CRH rises exponentially towards term, which has been called the placental clock.

Why is "Inhibin A hormone" not the answer?

Inhibin A is a screening marker in the quadruple test and does not time labour.

Why is "Relaxin hormone" not the answer?

Relaxin softens the cervix and pelvic ligaments but does not follow an exponential late rise like this.

Why is "Human placental lactogen" not the answer?

Human placental lactogen mediates maternal metabolic adaptation and does not time labour.

What concept does this question test?

It tests Labour and delivery: placental CRH in OBG. It stimulates fetal adrenal DHEA sulphate (the substrate for placental oestrogen) and enhances the effect of prostaglandins on the myometrium.

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 Labour and delivery: placental CRH?

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.