9: Pelvic Dimensions

Question 1

Narrowest part:

Answer 1

Ischial spines! Must be >10cm to have a chance of vaginal delivery

Question 2

Pelvic Inlet A-P

Answer 2

middle of sacral promontory to upper margin of symphysis pubis; “true conjugate”
11cm or >

Question 3

Pelvic Inlet Transverse

Answer 3

greatest diamete bet linea terminalos

13cm

Question 4

Pelvic Inlet Obliques

Answer 4

SI jt to ileopectineal eminence

12.75cm

Question 5

Pelvic Inlet Obstetric conjugate

Answer 5

shortest A-P distance

=diagona; conjugate- 1.5/2cm

Question 6

Pelvic Outlet pos triangle

Answer 6

line between 2 ischial tuberosities with apex at tip of sacrum

Question 7

Pelvic Outlet ant triangle

Answer 7

pubic arch with base also the line between the 2 ischial tuberosities

Question 8

Midpelvis

Answer 8

important! interspinous ~10cm

Question 9

Optimizing pelvic size

Answer 9

squatting squatting squatting

pressure on SI jts during contractions

Question 10

Estimating pelvic inlet

Answer 10

insert fingers vaginally, raise until hit pubic arch

palpate coccyx for mobility

Question 11

Estimating pelvic midpelvis

Answer 11

check ischial spines for prominence

palpate curve of sacrum, deeper the better

Question 12

Estimating pelvic outlet

Answer 12

use fist between ischial tuberosities