Question:easy
Which of the following pelvic measurements is most commonly used clinically?
Which of the following pelvic measurements is most commonly used clinically?
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Which conjugate can the examining fingers reach and measure during a vaginal exam?
Updated On: Jun 24, 2026
- Diagonal conjugate
- Anteroposterior diameter of the inlet
- Transverse diameter of the outlet
- Oblique diameter of the pelvis
Show Solution
The Correct Option is A
Solution and Explanation
Step 1: The key idea is which pelvic dimension a clinician can actually reach and measure with the examining hand at the bedside. Most internal pelvic diameters are out of reach, so the choice is narrow.
Step 2: During a vaginal examination the fingertips can stretch from the under-surface of the pubic symphysis up to the sacral promontory. That span is the diagonal conjugate, about $12$ cm, and it is the standard clinical measurement made to estimate inlet adequacy.
Step 3: From this value the obstetric conjugate is calculated indirectly by deducting $1.5$ to $2$ cm, which is why the inlet anteroposterior diameter itself, option (b), is never measured directly. The outlet transverse diameter, option (c), and the oblique diameter, option (d), are not part of the routine first-line clinical assessment.
Step 4: Therefore the measurement used most often in clinical pelvimetry is the diagonal conjugate.
\[\boxed{\text{Diagonal conjugate}}\]
Step 2: During a vaginal examination the fingertips can stretch from the under-surface of the pubic symphysis up to the sacral promontory. That span is the diagonal conjugate, about $12$ cm, and it is the standard clinical measurement made to estimate inlet adequacy.
Step 3: From this value the obstetric conjugate is calculated indirectly by deducting $1.5$ to $2$ cm, which is why the inlet anteroposterior diameter itself, option (b), is never measured directly. The outlet transverse diameter, option (c), and the oblique diameter, option (d), are not part of the routine first-line clinical assessment.
Step 4: Therefore the measurement used most often in clinical pelvimetry is the diagonal conjugate.
\[\boxed{\text{Diagonal conjugate}}\]
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