One of the following features can be used to define contracted pelvis :

Ans. is a i.e. Transverse diameter of inlet is 10 cm Minimal / Critical diameters of the Pelvis : (If any of the following diameter is less than critical diameter, Pelvis is said to be contracted) Inlet Mid pelvis Outlet Obstetric conjugate = 10 cms Interspinous diameter = 10 cms Inteuberous diameter = 8 cms Diagonal conjugate = 11.5 cm Transverse diameter = 12 cms Mid pelvis is said to be contracted when sum of interspinous diameter (Avg. = 10.5 cm) and posterior sagittal diameter (5 cm) falls from 15.5 cm to 13.5 cms. It can be clinically suspected when the inteuberous diameter does not admit four knuckles. Another way of defining contracted pelvis is where the essential diameters of one or more planes are shoened by 0.5 cms. In the question it is clearly evident that Transverse diameter (10 cms) is too sho and is therefore contracted. Gynaecoid, Anthropoid, Android and Platypelloid pelvis are variations of normal female pelvis. These varieties are not necessarily contracted, although there may be a detion of normal mechanism of labour. Extra edge: In women with contracted pelvis, face and shoulder presentations are encountered three times more frequently, and cord prolapse four to six times more often.