Pelvis and pelvic floor

Question 1

How many bones in the pelvis?

Answer 1

4: symphysis pubis +2 Innominate bones + coccyx

Question 2

What are the main types of pelvis?

Answer 2

gynaecoid (best for childbearing)
android
anthropoid
platypelloid (flat)

Question 3

What are the diameters of female pelvis?

Answer 3

AP Oblique Transverse
Brim 11 12 13
Cavity 12 12 12
Outlet 13 12 11

Question 4

When does the pelvic girdle pain usually resolve after pregnancy?

Answer 4

By 6 weeks after birth should go back to pre-pregnant state. Symphysis Pubis Disfunction.

Question 5

At what station should the head be at full dilatation?

Answer 5

Ideally near 0 or at + stations. Stations - relationship between presenting part and imaginary line on ischial spine level.

Question 6

Name the superficial muscles of the perineum.

Answer 6

Superficial transverse perineal muscle
Bulbospongiosus (Bulbocavernosus) muscle
Ischiocavernosus muscle

Question 7

What is the nerve supply of the perineum?

Answer 7

Derived from the pudendal nerve:

provided by 3rd and 4th sacral nerves.

Question 8

Name the deep muscles of the perineum (levator ani muscles)

Answer 8

Pubococcygeus (pubovisceral)
         -puboperinealis
         -pubovaginalis
         - puboanalis
Puborectalis
Illiococcygeus
(levator ani muscle trauma occurs in 13-36% of women who have vaginal birth).
2nd, 3rd and 4th sacral nerves

Question 9

How can you decrease the chance of perineal trauma?

Answer 9

• perineal massage from 34 weeks
• left lateral position associated with less trauma (squatting/standing with more)
• warm compresses
• slowing down when head is crowning