Labour and delivery: anthropoid pelvis: 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: anthropoid pelvis

Sample item

On clinical pelvimetry, a woman's pelvic inlet is oval, with the anteroposterior diameter greater than the transverse diameter, and the sacrum is long. Which pelvic type is this, and which fetal position does it favour?

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

The answer and the reasoning

C. Anthropoid, favouring occipito-posterior lie

The anthropoid pelvis has an inlet longer anteroposteriorly than transversely and favours direct occipito-anterior or occipito-posterior engagement, with a high rate of persistent posterior positions. The gynaecoid pelvis has a rounded inlet, the android a heart shape, and the platypelloid is flat and wide.

Option by option

  • A. Android, favouring deep transverse arrest

    Android has a heart-shaped wedge inlet with a narrow forepelvis, which is not the shape described here.

  • B. Platypelloid, favouring transverse engagement

    Platypelloid has a transversely oval flat inlet with a shortened anteroposterior diameter.

  • C. Anthropoid, favouring occipito-posterior lie (correct)

    Correct. The anteroposteriorly oval inlet of the anthropoid pelvis favours direct occipito-posterior positions.

  • D. Gynaecoid, favouring occipito-anterior position

    Gynaecoid has a rounded inlet with transverse diameter slightly longer than the anteroposterior.

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, Anthropoid, favouring occipito-posterior lie. The anthropoid pelvis has an inlet longer anteroposteriorly than transversely and favours direct occipito-anterior or occipito-posterior engagement, with a high rate of persistent posterior positions.

Why is "Android, favouring deep transverse arrest" not the answer?

Android has a heart-shaped wedge inlet with a narrow forepelvis, which is not the shape described here.

Why is "Platypelloid, favouring transverse engagement" not the answer?

Platypelloid has a transversely oval flat inlet with a shortened anteroposterior diameter.

Why is "Gynaecoid, favouring occipito-anterior position" not the answer?

Gynaecoid has a rounded inlet with transverse diameter slightly longer than the anteroposterior.

What concept does this question test?

It tests Labour and delivery: anthropoid pelvis in OBG. The gynaecoid pelvis has a rounded inlet, the android a heart shape, and the platypelloid is flat and wide.

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: anthropoid pelvis?

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.