What is the type of pelvis called that has a long, oval brim/inlet where the anteroposterior diameter is longer than the transverse diameter?

1. A

   Gynecoid pelvis

2. B

   Android pelvis

3. C

   Anthropoid pelvis

4. D

   Platypelloid pelvis

Appeared in: MP CHO - 2022

Explanation

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• The Anthropoid pelvis is defined by its unique shape, where the pelvic inlet is a long, narrow oval, elongated in the anteroposterior (front-to-back) direction.
• This means its anteroposterior (AP) diameter is significantly longer than its transverse (side-to-side) diameter.
• This shape is less common than the gynecoid type but is still found in about 25% of women.
• Due to the elongated AP diameter, the fetal head often engages in an occipito-posterior (OP) position, which can sometimes lead to a longer labor.

Why Other Options Were Wrong

• Option A: The Gynecoid pelvis has a round or slightly oval inlet, where the transverse diameter is typically equal to or slightly longer than the anteroposterior diameter, not the other way around.
• Option B: The Android pelvis has a narrow, heart-shaped or triangular inlet. It is not characterized by a long oval shape with a dominant anteroposterior diameter.
• Option D: The Platypelloid pelvis is the opposite of the anthropoid type. It has a flattened, kidney-shaped inlet where the transverse diameter is much longer than the anteroposterior diameter.

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Clinical Relevance

• Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Classification of female pelvis types based on anatomical shape and diameters as background academic context rather than a clinical decision trigger.
• Understanding pelvic types is crucial for nurses and midwives to anticipate potential labor patterns and complications.
• A woman with an anthropoid pelvis is more likely to have a fetus in the occipito-posterior (OP) position. This can lead to prolonged labor and intense back pain ('back labor') for the mother. Nurses should be prepared to assist with positioning changes (e.g., hands and knees, pelvic rocking) to help rotate the fetus.
• What if? If a woman with an anthropoid pelvis has a fetus in the occipito-anterior (OA) position, labor may progress more smoothly, but the elongated shape of the pelvis still needs to be considered during the descent of the fetal head.

How to Approach the Question

• First, identify the key descriptive terms in the question: 'long, oval brim/inlet' and 'anteroposterior diameter is longer than the transverse diameter'.
• This is a factual recall question based on anatomical knowledge. You need to match the description to one of the four main pelvic types.
• Mentally review the characteristics of each pelvic type.
• Gynecoid is round and ideal. Android is heart-shaped (male-like). Platypelloid is flat and wide transversely.
• Anthropoid is the only type that is elongated in the anteroposterior direction.
• Select the option that matches the description of a vertically long, oval inlet.

Concept Tested & Keywords

• Concept Tested: Classification of female pelvis types based on anatomical shape and diameters.
• Stem keywords: pelvis, long, oval brim, inlet, anteroposterior diameter, transverse diameter
• Lead-in keywords: What is the type

Question ID

Q_jMML8YSWVYWA-kneESA7

Copy ID

Reference Book

E6 Midwifery Obstetrics and Gynecology Nursing Sandeep Kaur p. 38-46

E6 Obstetrics Williams p. 16-32