Gynecoid pelvis

Gynaecoid pelvis

ADVANCED DIPLOMA IN MIDWIFERY
MWMS 4013

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The Bony Pelvis

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The Bony Pelvis

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REGION OF THE PELVIS

False Pelvis False Pelvis
True Pelvis
Abdominal Cavity
Containing abdominal organ

True Pelvis :

Pelvic inlet
Pelvic outlet

Pelvic cavity

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Borders of pelvic inlet (Brim) ‫زو هارون‬

Sacral promontory 
Sacral ala or wing 
Sacroiliac joint 
Iliopectineal line 
Iliopectineal eminence 
Superior ramus of the pubis bone 
Upper inner border of the pubic bone 
Upper inner border of the symphysis pubis 

Pelvic Cavity

The hollow of sacrum
Greater sciatic notch
Posterior of the acetabulum
Obturator foramen & obturator membrane
Posterior body of symphysis pubis
Posterior of the symphysis pubis

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Pelvic Outlet

Lower border of symphysis pubis
Ischial spines / ischial tuberosity
Sacrospinous ligament
Lower border of the sacrum

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DIAMETER OF THE BRIM

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ANTERIOR POSTERIOR (AP) DIAMETER OF THE BRIM
CONJUGATE

Anatomical (True) Obstetrical Diagonal

• 12 cm • 11 cm • 13.5
• Measured • Measured • Measured

between sacral between sacral between sacral
promontory to the promontory to the promontory to the
uppermost point posterior border lower border of
of the symphysis of the upper the symphysis
pubis surface of the pubis
symphysis pubis
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ANTERIOR POSTERIOR (AP) DIAMETER

12cm
11cm
13.5cm

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DIAMETER OF THE BRIM

AP Diameter

• 11 cm
• Obstetrical conjugate

Oblique Diameter

• 12 cm
• Extend from the iliopectineal eminence to the

sacroiliac joint on the other side

Transverse Diameter

• 13 cm
• Constructed at the right angles of the AP diameter

and extends across the greatest width of th‫ن‬e‫رو‬b‫ا‬r‫ه‬im‫زو‬

DIAMETER OF THE CAVITY

The cavity is circular in shape and
although it is not possible to measure

the diameter exactly, they are all
considered to be 12 cm

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DIAMETER OF THE OUTLET

AP Diameter

• 13 cm
• Extend from the lower border of the symphysis

pubis to sacrocoxygeal joint

Oblique Diameter

• 12 cm
• Extend between the obturator foramen to the

sacrospinous ligament

Transverse Diameter

• 11 cm
• Between two ischial spine

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HOW TO REMEMBER?

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Pelvic inclination

• The pelvic brim and pelvic outlet is not
located in the horizontal plane when
the subject stands erect.

• The planes of pelvic inlet and pelvic
outlet incline downward from behind
forward.

• Consequently the plane of pelvic inlet

creates an angle of 55 – 60% to the

horizontal plane and the plane of

pelvic outlet forms an angle of 15 with

the horizontal plane ‫زو هارون‬

Functions of the bony pelvis

• To allow the movement of the body especially walking &
running.

• Permit the person to sit & kneel

• Women’s pelvis adapted for childbearing

• Acting as bridge between the femur, transmit the weight of
trunk to the leg

• Protection of pelvic organ

• Sacrum transmits the cauda equine and distribute the nerve
to various part of the pelvis

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