Types of pelvis and their significant

ADVANCED DIPLOMA IN MIDWIFERY
SEMESTER I

MWMS 4013
Types of pelvis and

their significant

‫زو هارون‬

‫زو هارون‬

‫زو هارون‬

LANDMARKS

TO DIFFERENTIATE Brim
THE TYPES OF Fore pelvis
PELVIS Side walls
Ischial spine
‫زو هارون‬
Sciatic notch
Subpubic angle
Sacrum
Cavity

LANDMARK GYNAECOID PELVIS IMPLICATION
Brim
Fore pelvis CHARECTERISTICS
Side walls
Ischial spine Rounded The most common pelvic
Sciatic notch Generous type in women (50%)
Subpubic angle Straight
Sacrum
Blunt The best type for
Cavity Generous childbearing
90˚

Well curved

Shallow ‫زو هارون‬

LANDMARK ANDROID PELVIS IMPLICATION
Brim
Fore pelvis CHARECTERISTICS Favor an occipito-posterior
Side walls position because of for pelvis
Ischial spine Heart shape narrow
Sciatic notch Narrow
Subpubic angle Convergent Ischial spine prominent prevent
Sacrum Prominent complete internal rotation of the
head and anterior posterior
Cavity Narrow diameter becomes caught
< 90˚ causes deep transverse
Straight arrest

Deep – funnel shape Narrowed sub pubic arch
cannot accommodate biparietal
diameter of the head and
displace the head backward

Funnel shape may hinder
progress of labour

‫زو هارون‬

ANTHROPOID PELVIS

LANDMARK CHARECTERISTICS IMPLICATION
Brim
Fore pelvis Long and oval normal delivery
Side walls
Ischial spine Narrow position in direct occipito
Sciatic notch Divergent posterior or occipito anterior
Subpubic angle Blunt position
Sacrum Wide
> 90˚ Present long diameter of head
Cavity Long in anterio posterior diameter
brim
Deep and concave
Occiput at hollow of sacrum ,
fetus pass through pelvis in
same position and delivered in
reduced occipito posterior
position

‫زو هارون‬

PLATYPELLOID PELVIS

LANDMARK CHARECTERISTICS IMPLICATION
Brim
Fore pelvis Kidney shaped With good uterine contraction
Side walls
Wide • Fetal head will push to the

Ischial spine Divergent Asynclitism – cavity- moulding due to
Blunt lateral tilting pressure of process
of the head asynclitism

Sciatic notch Wide Increase of transverse
Subpubic angle diameter and decrease of
Sacrum > 90˚ anterior posterior diameter .
• fetal head will descend
Straight
Engagement of fetal head -
Cavity ‫زو هارون‬ Shallow there is a space will tilted to suit with the
for fetal head to descent narrow anterior posterior
diameter of pelvic brim

Biparietal diameter arrested
at sacrocotyloid diameter
pelvic brim