Type of pelvis

The pelvis is divided into two parts-

  •  The true 
  • False pelvis

False pelvis-The false pelvis is called as The Greater or pelvis major is the part of the pelvis situated above the pelvic brim. It is formed by the upper flared-out portions of the iliac bones and protects the abdominal organs. It supports the intestines, and transmits part of their weight to the anterior wall of the abdomen. It is of no obstetrical significanoe.

True pelvis -The true pelvis is called as The Lesser or pelvis minor the bony canal though which the fetus must pass during birth. It is situated below and behind the pelvic brim. Its bony walls are more complete than those of the greater pelvis. It is bounded at the back by the sacrum, at the sides by the ischium and in tront by the pubis, forming a solid ring of bone. It has a brim, a cavity and an outlet.

Types of Pelvis-

  • The Gynaecoid or genuine female pelvis
  • The Android pelvis
  • The Anthropoid pelvis
  •  The Platypelloid pelvis

Gynaecoid pelvis-

Normally 50% of females have this type of pelvis

  • Ischial spine are blunt
  • Sidewalls are straight.
  • Sacrosciatic notch is wide
  • Sacrum is wide with average concavity
  • Subpubic angle is 90-100 degrees
  • Inlet is slightly oval

Android pelvis-

  • Nearly 20% of females have this type of pelvis.
  • It is also known as male pelvis.
  • Inlet is heart -shaped/Triangular
  • Side wall are converging
  • Ischial spine are projecting
  • Sacro-sciatic notch is narrow.
  • Subpubic angle is narrow <90 degrees.

Anthropoid pelvis-

  • 25% of female have this type of pelvis.
  • Structure is ‘ape-like’
  • Sacro-sciatic notch is wide.
  • Sacrum is long and narrow.
  • Subpubic angle is narrow.
  • All transverse diameters are short.
  • All anteroposterior diameters are long

Platypelloid pelvis-

  • Only 5%of female have this type of pelvis.
  • It is flat type
  • Sacro-sciatic notch is narrow.
  • Subpubic angle is wide.
  • All transverse diameters are long.
  • All anteroposterior diameters are short.

Difference in male and female pelvis-

Characteristics Male pelvis Female pelvis
Size Smaller Larger
Greater sciatic notch Narrower Wider
Inferior pubic angle Narrowrer Wider
False pelvis Tall Flared
Pelvic inlet Android Gynecoid
Pelvic outlet Smaller Larger