Session 4 - Part II

Question 1

What are the ‘good’ characteristics of a pelvis for childbirth?

Answer 1

Round pelvic inlet
Straight side walls
Ischial spines not too prominent (So don’t protrude into the pelvic cavity)
Well rounded greater sciatic notch
Well curved sacrum (Helps accommodate the foetal head)
Sub pubic arch >90 degrees

Question 2

What is the false pelvis?

Answer 2

The greater pelvis (Has no obstetric relevance)

Question 3

What is the true pelvis?

Answer 3

The lesser pelvis (Bony canal, solid and immobile)

Question 4

What is the Pelvic conjugate?

Answer 4

The antero-posterior diameter of the pelvis (Pelvic inlet)

Question 5

How is the Obstetric conjugate measured?

Answer 5

Sacral promontory to the midpoint of the pubic symphysis

Question 6

How is the Diagonal conjugate measured?

Answer 6

Sacral promontory to the inferior border of the pubic symphysis

Question 7

What are the 2 main ligaments of the pelvis?

Answer 7

Sacrospinous ligament (Sacrum to ischial spine)
Sacrotuberous ligament (Sacrum to ischial tuberosity)

Question 8

What are the properties of a Gynecoid pelvis?

Answer 8

Circular pelvic inlet
80 - 85 degree angle
Well rounded greater sciatic notch

Question 9

What are the properties of a Android pelvis?

Answer 9

Funnel shaped
Heart shaped pelvic inlet
50 - 60 degree angle
Smaller bispinous diameter
Prominent projecting promontory
Prominent medially projecting ischial spines

Question 10

How does the pelvis aid childbirth?

Answer 10

The posterior wall of the outlet has ligaments which are softer so can stretch
The coccyx (Usually projecting in) moves out of the way during delivery