Postpartum haemorrhage and emergencies: ergometrine and trapped placenta: 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 · Postpartum haemorrhage and emergencies: ergometrine and trapped placenta

Sample item

Methylergometrine is mistakenly given intravenously at delivery of the anterior shoulder, before the placenta has come out. Which complication is most likely?

AWater intoxication with hyponatraemiaBProlonged atony from oxytocin receptor desensitisationCUterine inversion from sudden loss of uterine toneDTonic uterine contraction with cervical spasm trapping the placenta

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

The answer and the reasoning

D. Tonic uterine contraction with cervical spasm trapping the placenta

Ergot alkaloids cause a sustained tonic contraction rather than rhythmic contractions, and the cervix can clamp down. The placenta may be trapped, and an undiagnosed second twin can be trapped as well. This is why ergometrine is not given before the placenta is delivered.

Option by option

A. Water intoxication with hyponatraemia
Water intoxication results from prolonged high-dose oxytocin infusion with free water.
B. Prolonged atony from oxytocin receptor desensitisation
Receptor desensitisation follows prolonged oxytocin exposure, not a single ergot dose.
C. Uterine inversion from sudden loss of uterine tone
Inversion follows traction on a relaxed uterus, which is the opposite of the ergot effect.
D. Tonic uterine contraction with cervical spasm trapping the placenta (correct)
Correct. Tonic contraction and cervical spasm can trap the placenta or an undiagnosed twin.

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, Tonic uterine contraction with cervical spasm trapping the placenta. Ergot alkaloids cause a sustained tonic contraction rather than rhythmic contractions, and the cervix can clamp down.

Why is "Water intoxication with hyponatraemia" not the answer?

Water intoxication results from prolonged high-dose oxytocin infusion with free water.

Why is "Prolonged atony from oxytocin receptor desensitisation" not the answer?

Receptor desensitisation follows prolonged oxytocin exposure, not a single ergot dose.

Why is "Uterine inversion from sudden loss of uterine tone" not the answer?

Inversion follows traction on a relaxed uterus, which is the opposite of the ergot effect.

What concept does this question test?

It tests Postpartum haemorrhage and emergencies: ergometrine and trapped placenta in OBG. The placenta may be trapped, and an undiagnosed second twin can be trapped as well. This is why ergometrine is not given before the placenta is delivered.

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 Postpartum haemorrhage and emergencies: ergometrine and trapped placenta?

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.