This document discusses the relationship between the fetus and the pelvis during childbirth. It describes the lie or orientation of the fetus, the presenting part of the fetus that engages the pelvis, and the position and attitude of the fetal head. The key points are: - The fetus most commonly lies longitudinally in the uterus with the head engaging the pelvis (cephalic presentation). - The position describes the location of the presenting part, such as the occiput, in relation to maternal pelvic quadrants. - The attitude refers to the flexion or extension of fetal parts. Flexion is most common with the head flexed forward onto the chest. - Moulding, or shifting of fetal

1. RELATION BETWEEN
FETUS & PELVIS

2.  LIE
 PRESENTATION
 PRESENTING PARTS
 ATTITUDE
 DENOMINATOR
 POSITION
 CEPHALIC PROMINENCE

3.  LIE
 The relationship b/w the long axis
of fetal ovoid to the long axis of
uterine ovoid
LONGITUDINAL LIE
TRANSVERSE LIE
OBLIQUE LIE

5.  PRESENTATION
 That part of the fetus that lies over
the pelvic inlet & occupies the lower
poles of the uterus
 3 presentation
CEPHALIC
PODALIC/BREECH
SHOULDER

7.  PRESENTING PARTS
 The most dependant part of the fetus,
which is felt first on vaginal
examination
In cephalic presentation depending upon
degree of flexion,
vertex
brow
face
deflexed head

8.  In breech presentation
 Flexed breech (fetal legs may be
flexed)
 Extended breech (extended at
knees)
 Footling breech (completely
extended)

10.  ATTITUDE
 The relation of fetal parts to each
other
 Main attitudes
FLEXION
EXTENSION

11.  TYPICAL FETAL
ATTITUDE
 universal flexion
with head flexed
over chest, arms
& legs flexed in
front of the body
and back curved
forward

12. Anteroposterior diameters of
the fetal skull
AP diameter Attitude Presenting part
Suboccipitobregmatic 9.4 Complete flexion Vertex occipitoanterior
cm
Suboccipitofrontal 10.5 Incomplete flexion Vertex
cm occipitoposterior
Occipitofrontal 11 cm Deflexion Vertex
occipitoposterior
Verticomental 13.5 cm Extension Brow
Submentobregmatic 9.4 Complete extension face
cm

14.  DENOMINATOR
 An arbitrarily chosen point on the
presenting part of the fetus which
is used to describe the position.

15. Presentations of the fetus
Presentation Attitude Denominator
Cephalic
vertex occipitoanterior Flexion Occiput
vertex occipitoposterior Deflexion occiput
brow Extension brow
face Complete extension Chin or mentum
Podalic or breech sacrum
shoulder acromion

16. Frequency of lie and
presenting part
Lie Presentation and
presenting part
Longitudinal 99.5% Vertex 96%
Transverse or oblique 0.5% Face 0.5%
Brow 0.5%
Breech 3%
Shoulder 0.5%

17.  POSITION
 The relationship
of the
denominator to
the four
quardrants of the
maternal pelvis.

18.  In vertex presentation
 Left occipitoanterior(common)
 Left occipitotransverse
 Left occipitoposterior
 Right occipitoanterior
 Right occipitotransverse
 Right occipitoposterior

20. Occipitoanterior

21. Left occipitoposterior

22. LeftOccipitoanterior

23. LeftOccipitotransverse

24. Occipitoposterior

25.  CEPHALIC PROMINENCE
 The most prominent part of the
head palpable per abdomen
 Produced by flexion and
extension of the head
 Vertex presentation (head well
flexed)
occiput is lower than sinciput
(can be felt on the side opposite
to the back)

26.  When the presenting part is face
or brow (extension of head)
sinciput is lower than
occiput (can be felt on the same
side of the back)
 Cephalic prominence can be
palpated by the second pelvic
grip

27.  When no cephalic prominence is
felt, there is neither flexion nor
extension and the attitude is one
of deflexion . This is also called
military position

28.  Longitudinal lie commoner –fetus
being an ovoid accommodates itself
easily along the long axis of the
uterine ovoid
 Cephalic presentation commoner -the
head being heavier and more
compact , due to gravitation, comes to
occupy lower pole and bulkier breech
adapts to the fundus of uterus ,which
is roomier

29.  MOULDING
 Cranial bones are connected by
membrane and this allows
considerable shifting or sliding of each
bone to accommodate to the maternal
pelvis.
 Frontal and occipital bone pass under
parietal bone.
 Posterior parietal is subject to more
pressure by the sacral promontory , it
passes under anterior parietal.

30. MOULDING (conti…..)
Thus there is compression of the
presenting diameter with compensatory
bulging of the diameter at right angles
Eg: in occipitoanterior head is
compressed in the presenting
suboccipitobregmatic and elongated in
the verticomental diameter .

31.  Moulding is assessed on vaginal
examination at two sites
parietal-parietal
parietal-occipital
• disappears a few hrs after birth
• Protective mechanism & prevents the
fetal brain from compression as long
as it is not excessive or not rapid

32.  GRADING
 Grade 1 / +moulding
:obliteration of suture line
 Grade 2 / ++moulding : reducible
overlap
 Grade 3 /+++moulding:irreducible
overlap (pathological )

33.  Clinical significance
 Some amount of moulding is beneficial
and this is one of the factors which
decide the success of a trial of labour
 Severe moulding can lead to
intracranial haemorrhage
 The site of moulding gives information
about the position of the head

34. Thank you