Last reviewed 01/2018

Pelvimetry is the measurement of the size of the pelvis, and hence the amount of space available for the fetus to squeeze through during birth.

Normal values are as follows:

  • Inlet: AP= 11.5 cm; transverse = 13.5 cm
  • Mid-cavity: AP= 12.5 cm; transverse = 12.5 cm
  • Outlet: AP = 13.5 cm; transverse = 11.5 cm

If on a radiograph the sizes appear to be significantly less than this, then there may be problems with obstructed labour.