female pelvis for nursing GNM student

2. Definition
It is a bony canal in
which fetus must pass
through during the time
of delivery.

4. Gynecoid
Android
Anthropoid
Platypelloid

5. THE GYNECOID PELVIS
 It is found in 50-55% of women.
 It has slightly oval inlet.
 The ischial spines are not prominent.
 This structure facilitates the passage
of the fetus during labour and delivery.

6. THE ANDROID PELVIS
 Also known as the male pelvis.
 It has a heart shaped outline.
 It has a wedge shaped inlet.
 Anterior pelvis and the suprapubic arch
are narrow.
 The ischial spines are prominent.
 The sacrum inclines forward in the
pelvis with little or no curvature.
 The sacro sciatic notch is narrow.
 Women with android pelvis(usualy 20%)
usually need caesarean deliveries.

7. THE ANTHROPOID PELVIS
 This is oval in shape.
 It has a large anterio posterior
diameter.
 The anterior and posterior segments
are narrow and pointed.
 The walls are straight.
 The ischial spines are prominent.

8. THE PLATYPELLOID PELVIS
 It is rare.(3% of women)
 It has a flattened gynaecoid shape.
 The inlet is oval.
 It has a wide tranverse diameter and a
short anteroposterior diameter.
 Posterior segment is flat.
 The inter spinous diameter is wide.

9. Comparison of Male and Female Pelvic
Structure
Characteristic Female Male
Bone thickness
Lighter, thinner, and
smoother
Heavier, thicker,
and more
prominent
markings
Pubic
arch/angle
80˚–90˚ 50˚–60˚
Acetabula Small; farther apart
Large; closer
together
Sacrum
Wider, shorter; sacral
curvature is accentuated
Narrow, longer;
sacral promontory
more ventral
Coccyx
More movable;
straighter
Less movable;
curves ventrally

11. Gynecoid pelvis
 Female
pelvis
 Shape is
ideal for
child
bearing

12. Pelvis is composed of four bones
Two
Innominate
bones
Coccyx Sacrum

13. Two Innominate bones

14. ILIUM
 Ilium is the largest portion of bone of the pelvis.
 The greater part of the inner aspect is smooth and concave,
forming the iliac fossa.
 The ridge which surmounts the two surfaces is known as
iliac fossa.
 Anteriorly the crest ends in the anterior iliac spine, a bony
prominence which can be readily palpated under the skin.
 Posteriorly it ends in the posterior superior iliac spine.
 These dimples will be seen to form the lateral angles of a
flat diamond shaped area, known as the rhomboid of
michaelis.
 Below the anterior superior iliac spine is another bony
prominence, called anterior inferior iliac spine.
 Similarly posterior inferior iliac spine situated posteriorly.

15. ILIUM
 At its lowermost part the ilium forms 2/5th of the
acetabulum.
 Behined the acetabulum, the ilium forms the upper part
of a large notch known as greater sciatic notch.
 On the inner aspect of the bone, the iliac fossa is
bounded below by a prominent ridge, known as ilio
pectineal line.
 Anteriorly the ilio-pectineal line swells into a bony
prominence at the point where the ilium fuses with the
superior ramus of the pubis and forms the ilio pectineal
eminence.
 Posterior to the ilio pectineal line, and above to the
greater sciatic notch ,is a rough area where the ilium
articulates with the sacrum to form the sacro iliac joint.

16. ISCHIUM
 The ischium is the lowest of the constituent bones of the
innominate bone, and is formed by the following parts:
1. The head forms the lowest 2/5th of the acetabulum, where it
fuses with the ilium and pubis.
2. Below the acetabulum a thick buttress of bone passess
downwards and terminates in the ischial tuberosity.
3. It is the part of the pelvis on which the weight of the body
rests when sitting.
4. Passing upwards and inwards from the ischial tuberosity a
small shaft of ischium becomes continuous with the
inferior ramus of the pubis, so forming the pubic arch.

17. ISCHIUM
5. The ischium thus forms the lower boundary
of a large foramen called as obturator
foramen or foramen ovale.
6. Above the tuberosity is a conspicuous
projection known as the ischial spine.
7. The lesser notch is situated between the
ischial spine above and the ischial tuberosity
below.

18. PUBIS
This is the smallest of the three bons forming
the innominate bone and it is only one which articulates with
its fellow of the opposite side.
 Pubis is square shaped
 Joint between two pubic bone is known as symphysis pubis.
 The upper surface of the body forms a crest known as the
pubic crest.
 This lateraly ends in the pubic tubercle.
 Below the body of the pubis the inferior ramus passess
downwards and outwards to join the ischium, forming the
upper part of the pubic arch.

19. THE SACRUM
It is situated in the posterior part of the pelvis,where it articulates
with the iliac portions of ytwo innominate bones at the sacro
iliac joints.
 It consists usually of five sacral vertebrae.
 The anterior surface is smooth.
 Concave in shape.
 The first sacral vertebra overhangs the sacral hollow, and its
upper projecting margin is known as the promontory of the
sacrum.
 The lower margin of the sacrum forms a small smooth
sueface where it articulates with the coccyx at the sacro-
coccygeal joint.

20. THE COCCYX
 It consists of four fused coccygeal vertebra.
 Triangular in shape.
 The first coccygeal vertebra articulates with lower
end of sacrum at the sacro- coccygeal joint.

21. Four bones are united together by
four joints
Two
Sacroiliac
joints
Sacro-coccygeal
joint
Symphysis
Pubis

22. SACRO ILIAC JOINT
It is formed with articulation
of sacrum with ilium. The
range of movements
Increased during
pregnancy under
the influence of
hormon relaxin
from placenta.

23. SYMPHYSIS PUBIS
 It is the joint between two pubic bones.
 This joint consist of an oval disc of fibro
cartilage,.
 About 1.5” long,which is interposed
between the bodies of the two pubic bones.
 It is reinforced by supporting ligaments
which pas from one pubic bone to another
in front, behind, above and below

24. SACRO-COCCYGEAL JOINT
It is a small joint situated between the lower
border of the sacrum and the upper border of
the coccyx.
 Slight back ward and forward movements
of the coccyx on the lower end of the
sacrum occur normally.
 The backward movement is greatly
increased during labour at the time of
actual birth of the head.

25.  Anatomically divided into two parts:
Gynecoid pelvis
True pelvis False pelvis

26. False pelvis
 It is bounded posteriorly by lumbar vertebrae and
laterally by the iliac fossa while in front boundary Is
formed by the lower portion of the anterior abdominal
wall
 Form by iliac portions of the innominate bone
 Limited above by the iliac crests.
 It is of no purticular obstetrical significant but serves
to support the intestines iomn non pregnant women
and support the enlarge uterus during pregnancy

27. True pelvis
 Chief concern to the obstetricians
 It forms the canal through which the fetus must pass
 Bounded above by the sacral promontory and alla of the
sacrum and upper margin of the pubic bone and below by the
pelvic outlet.
 The walls are partially bony and partially ligaments.
 Its posterior boundary is formed by anterior surface of the
sacrum measures 11.5 cm. and latteral boundary is furnished
by the inner surface of the ischial bones.
 It is Shallow in front,formed by symphysis pubis & measures
4cm.
 It lies below the level of the pelvic brim and this of great
importance.

28. True pelvis
Regions :
Inlet (brim)
Cavity
Outlet

29. Inlet (brim)
9 landmarks of inlet
Upper border of symphysis pubis
Pubic crest,
Pubic tubercle
Pectineal lines / superior rami of the
pubis.
Ilio-pectineal eminence
Ilio-pectineal lines
Sacroiliac joint
Anterior border of ala of sacrum
Sacral promontory

30. 9 landmarks of inlet

31. Inlet (brim)
Shape :
 Almost oval in shape with
Antero -posterior diameter
being the shortest.
 It is a flat surface and is known
as the plane of the brim.

32. Inlet (brim)
 Diameters
 Antero-posterior diameter:
True Conjugate:
Distance between the midpoint of the
sacral promontory to the inner margin of
the upper border of symphysis pubis.
(It measures 11 cm.)

33. Inlet (brim)
 Antero-posterior diameter:
 Obstetric conjugate:
Distance between the midpoint of
the sacral promontory to prominent
bony projection in the midline on the
inner surface of the symphysis pubis.
(It measures 10cm.)

34. Inlet (brim)
 Antero-posterior diameter:
 Diagonal conjugate:
Distance between the lower border
of symphysis pubis to the midpoint on
the sacral promontory.
(It measures 12cm.)

35. Inlet (brim)
 Transverse diameter:
Distance between two farthest points on the
Pelvic brim over the ilio-pectineal lines.
(It measures 13 cm.)
 Oblique diameter :
Two Oblique Diameters-left & Right
Each one extends from the one sacroiliac
joint to the opposite Iliopectineal eminence
(It measures 12 cm.)

36. Diameters

37.  Segment of the pelvis bounded above by the inlet &
below by the plane of least pelvic dimensions.
 Shape: Almost round
 Anterior wall consist of posterior surface of symphysis
pubis-1.5” deep.
 Posterior wall formed by the hollow of the sacrum-4.5”
deep.
 Lateral walls comprise of greater sciatic notch.
 The inner surface is smooth.
 The imaginary line from the mid point of the
symphysis pubis to the junction of 2nd & 3rd vertebrae
known as the plane of the cavity.

38.  Antero-posterior diameter:
It measures from the midpoint on the
posterior surface of the symphysis pubis to
the junction of 2nd or 3rd sacral vertebrae.
( it measures 12cm.)
 Transverse diameter: (12 cm.)
Cannot be precisely measure as the
point lie over the soft tissues covering the
sacrosciatic notch & obturator foramina.

39.  Obstetrical outlet:
 Extends from the lower border of the
symphysis pubis to the tip of ischial
spine posteriorly to meet the tip of 5th
sacral vertebra.
 Antero-posteriorly oval shape

40. Obstetrical outlet:
 Diameters
 Antero-posterior diameter:
Extends from the inferior border of the
symphysis pubis to the tip of the sacrum.
(It measures 11cm.)
 Transverse diameter:
Distance between the tip of two
ischial spines.
(it measures 10-10.5 cm.)

41.  Anatomical outlet:
 Bounded in front by lower border of
symphysis pubis, laterally by
ischiopubic rami ,ischial tuberosity
& sacrotuberous ligament,
posteriorly the tip of coccyx.
 Diamond shape.

42.  Anatomical outlet:
 Diameters
 Antero-posterior diameter:
Lower border of symphysis pubis to
the tip of coccyx
(It measures 13 cm.)
 Transverse diameter:
Distance between inner border
of two ischial tuberosities.
(It measures 11cm.)

43. 11cm;
10cm;
12cm
12cm
13cm;
11cm
12cm 12cm -
13cm 12cm 11cm;
10.5cm
Diameters

44. Pelvic Ligaments
1. The supporting ligaments:
Passes from the sacrum to the ilium, both
anterior and posterior to the joint cavity.
2. The sacro-tuberous ligament:
It is a strong ligament passing from the
posterior superior iliac spine and the lateral
borders of the sacrum and the coccyx to ischial
tuberocity.
3. The sacro spinous ligament:
It is a strong ligament passing from the
side of the sacrum and coccyx across the greater
sciatic notch to the ischial spine.

45. Pelvic Ligaments
4. The inguinal ligament:
It runs from anterior superior iliac
spine to the pubic tubercle.
5. The obturator membrane:
It is a ligament closing the foramen
ovale, with the exception of a small area
in its upper part.

46. BLOOD SUPPLY OF THE PELVIS
1. ARTERIAL BLOOD SUPPLY:-
OVARIAN ARTERIES.
INTERNAL ILIAC ARTERIES.
2. VENOUS BLOOD SUPLY
OVARIAN VEINS
INETRNAL ILIAC VEINS
NERVE SUPPLY OF THE PELVIS:
SYMPATHETIC AND PARA-
SYMPATHETIC NERVES

47. ADEQUACY OF THE PELVIS TO
ACHIEVE VAGINAL DELIVERY
WHAT IS MEANT BY CLINICALLY FAVORABLE
PELVIS?
 Sacral promontory can not be felt
 Ischial spines are not prominent
 Subpubic arch accept 2 fingers
 Intertuberous diameter accept 4 knuckles on pelvic exam

48. ADEQUACY OF THE PELVIS TO
ACHIEVE VAGINAL DELIVERY
WHAT IS THE OBSTETRIC CONJUGATE?
The shortest APD between sacral promontory &
symphysis pubis
Can only be measured radiologically
N > 10 cm

49. ADEQUACY OF THE PELVIS TO
ACHIEVE VAGINAL DELIVERY
 WHAT IS THE TRUE CONJUGATE?
 APD between promontory of the sacrum & superior margin of
the symphysis pubis
 WHAT IS THE DIAGONAL CONJUGATE?
 Distance between sacral promontory & inferior margin of the
symphysis pubis
 Measured clinically

50. MCQs
1. 50-55% women having ________ type of
pelvis.
A. Platypelloid
B. Android
C. Anthropoid
D. Gynecoid

51. 2. _______ type of pelvis also known as male
pelvis.
A. Platypelloid
B. Android
C. Anthropoid
D. Gynecoid

52. 3. Shape of the gynecoid pelvis is __________.
A. Oval
B. Slightly oval
C. Heart shaped
D. Kidney shaped

53. 4. ______ is a distance between the lower border
of symphysis pubis to the midpoint on the sacral
promontory.
A. Anatomical conjugate
B. Diagonal conjugate
C. Obstetrical conjugate
D. True conjugate

54. 5. Distance between lower border of symphysis
pubis to the tip of coccyx is ______cm.
A. 11cm
B. 10 cm
C. 13 cm
D. 12 cm

55. ANSWER KEY
1. D
2. B
3. B
4. B
5. C