Question
Consider the following statements regarding diameters of a normal female pelvis:
1. AP diameter is the shortest diameter at brim
2. Oblique diameter is the largest diameter of inlet
3. Diagonal conjugate cannot be directly measured
Which of the statements given above is/are correct?
| A. |
1 and 2 only |
| B. |
1, 2 and 3 |
| C. |
1 only |
| D. |
2 only |
|
Correct Answer » C Explanation |
 |
Statement 1 is correct: The Anteroposterior (AP) diameter, specifically the obstetric conjugate, is the shortest diameter of the pelvic inlet (brim). It typically measures approximately 10.5 cm to 11 cm, whereas the oblique and transverse diameters are larger.
Statement 2 is incorrect: The transverse diameter is the largest diameter of the pelvic inlet, measuring approximately 13 cm. The oblique diameter measures about 12 cm, making it intermediate between the AP and transverse diameters.
Statement 3 is incorrect: The diagonal conjugate is the only diameter of the pelvic inlet that can be measured directly during a clinical vaginal examination. It is measured from the lower border of the pubic symphysis to the sacral promontory. In contrast, the true (anatomical) and obstetric conjugates cannot be measured directly and must be estimated by subtracting 1.5–2 cm from the diagonal conjugate measurement.