3. CPD either due to :-
• The baby’s head is
proportionally too
large
• the mother’s pelvis is
too small
to easily allow the baby to fit
through the pelvic opening.
4. Causes :-
1. Large baby due to:
• Hereditary factors
• Diabetes
• Postmaturity (still pregnant
after due date has passed)
• Multiparity (not the first
pregnancy)
2. Abnormal fetal positions
3. contracted pelvis
4. Abnormally shaped pelvis
6. ContractedPelvis
Definition:
• Anatomical definition: It isapelvisin which
oneor more of its diametersisreduced
below the normal byoneor more
centimeters.
• Obstetric definition: It isapelvisin which
its size & shapeissufficiently abnormalthat
interferewithvaginaldeliveryofnormalsize
fetus
7. Factors influencing the size and shape
of the pelvis:
1. Developmental factor: hereditary or
congenital.
2. Racialfactor.
3. Nutritional factor: malnutrition results in
small pelvis.
4. Sexualfactor: asexcessiveandrogen may
produce android pelvis.
5. Metabolic factor: asrickets andosteomalacia.
6. Trauma, diseasesor tumours of the bony
pelvis, legsor spines.
9. 5.Naegele’spelvis: absenceof one
sacralala
6.Robert’s pelvis: absenceof both
sacralalae.
7. Highassimilation pelvis: The sacrum is
composedof 6 vertebrae.
8.Lowassimilation pelvis: The sacrum is
composedof 4 vertebrae.
9 .Split pelvis: splitted symphysispubis
10. • Causes in the pelvis
• Metabolic:
- Rickets.
- Osteomalacia(triradiate pelvic brim).
• Traumatic: asfractures.
• Neoplastic: asosteoma.
• Infection : TB
Etiology of ContractedPelvis
11. Causes in the spine
• Lumbar kyphosis
• Lumbar scoliosis
• Spondylolisthesis:
The5th lumbar vertebra with the above vertebral
column ispushed forward while the promontory is
pushed backwards and the tip ofthe sacrum is
pushed forwards leading to outletcontraction.
Etiology of ContractedPelvis
12. Causes in the lower limbs
• Dislocation of one or bothfemurs.
• Atrophy ofone or both lower limbs.
N.B.oblique or asymmetric pelvis: one oblique
diameter is obviously shorter than theother.
This canbe found in:
• Diseases,fracture or tumours affecting one
side.
Etiology of Contracted Pelvis
13. Pelvis
• History
• Rickets: is expected if there is ahistory of
delayed walking anddentition.
• Traumaor diseases: of the pelvis, spinesor
lower limbs.
• Badobstetric history: e.g. prolonged labour
ended by:
difficult forceps
caesareansection or
still birth.
14. •Examination
• General examination:
Gait:abnormal gait suggestingabnormalities in
the pelvis, spinesor lowerlimbs.
Height: women with lessthan 150cmheight
usualy havecontracted pelvis.
Spinesandlower limbs: mayhaveadiseaseor
lesion.( kyphosis,…)
Pelvis
15. •Examination
•General
examination:
Manifestations of rickets as:
square head
rosary beads in the costalridges.
pigeon chest
Harrison’s sulcus and bow legs.
Dystocia dystrophia syndrome: the
woman is
*short,obese stocky, subfertile, has android pelvis and
Pelvis
16. Abdominal examination:
Nonengagement of the head:
in the last 3-4 weeks in primigravida.
Pendulous abdomen:
in aprimigravida.
Malpresentations:
are morecommon.
Pelvis
17. • Pelvimetry:
It is assessmentof the pelvic diameters and capacity
done at 38-39weeks.It includes:
1. Clinical pelvimetry:
Internal pelvimetry for:
inlet
cavity
, and
outlet.
External pelvimetry for:
inlet and
outlet.
Pelvis
18. •Pelvimetry:
2.Imaging pelvimetry:
X-ray.
Computed tomography (CT).
Magnetic resonance imaging (MRI) .
• N.B.CTand MRI are recent and accurate but
expensiveandnot alwaysavailablesotheyare
not in commonuse.
Diagnosisof ContractedPelvis
19. Internal pelvimetry
isdone through vaginalexamination
1. Theinlet:
a.Palpation of the forepelvis (pelvicbrim):
Theindex andmiddle fingers aremovedalong
thepelvic brim. Note whether it isround or
angulated,causingthe fingersto dip into aV-
shapeddepressionbehind the symphysis.
b.Diagonal conjugate:
Tryto palpatethe sacralpromontory to
measurethe diagonal conjugate. Normally, itis
12.5 cm and cannot be reached. If it is felt the
pelvis is considered contracted and the true
conjugatecanbe calculatedby subtracting 1.5
cmfrom the diagonalconjugate .
This assessment
isnot done if the headisengaged.
20. Internal pelvimetry
2.Thecavity:
a.Height, thicknessandinclination of thesymphysis.
b. Shapeand inclination of thesacrum.
c. Side walls: Todetermine whether it is straight,
convergent or divergent starting from the pelvic
brim down to the baseof ischial spinesin the
direction of the baseof the ischial tuberosity.
Then relation between the index and middle
finger of the baseof ischial spines and the thumb
of the other handon the ischial tuberosity is
detected. If the thumb is medial the side wall is
convergent and if lateral itis divergent.
21. • 2.Thecavity:
• d.Ischial spines:
Whether it is blunt (difficult to identify at
all), prominent (easily felt but not large) or
very prominent (large and encroaching on
themid- plane).
Theischial spines canbe located by
following the sacrospinous ligament to its
lateral end.
Internal pelvimetry
22. 2.Thecavity:
e.Interspinous diameter: Byusing the 2
examining fingers, if both spines canbe
touched simultaneously, the interspinous
diameter is9.5 cmi.e. inadequate foran
average-sizedbaby
.
f. Sacrosciatic notch: If the sacrospinous
ligament is two and half fingers, the
sacrosciatic notch is consideredadequate.
Internal pelvimetry
23. 3-Theoutlet:
a. Subpubicangle: Normally, it admits 2fingers.
b. Mobility of the coccyx:by pressingfirmly on
it while an external hand on it candetermineits
mobility.
c.Anteroposterior diameter of the outlet: from
the tip of the sacrum to the inferior edge of
the symphysis.
Internal pelvimetry
24.
25. External pelvimetry
• Thom’s, Jarcho’s or crossing
pelvimeter can be used for
externalpelvimetry.
Interspinous diameter
(25cm): betweenthe
anterior superior iliac
spines.
Intercrestal diameter (28
cm): between the most far
points on the outer borders of
the iliac crests.
External conjugate (20cm(.
Bituberous diameter
(11cm)
26.
27. Radiological pelvimetry
• Lateral view:
The patient stands with the X-ray tube on one side
and the film cassetteon the opposite side.
it shows
the anteroposterior diameters of the pelvis,
angle of inclination of the brim, width of
sacrosciatic notch, curvature of the sacrum and
cephalo-pelvic relationship.
• Inlet view: Thepatient sits on the film cassette
and leans backwardssothat the plane of the
pelvic brim becomes parallel to thefilm.
• Outlet view: The patient sits on the film
cassetteand leans forwards.
28. Cephalometry
• Ultrasonography: is the safeaccurate and
easy method and candetect:
Thebiparietal diameter (BPD)
Theoccipito-frontal diameter.
Thecircumference of thehead.
• Radiology (X-ray: is difficult to interpret.
29. Cephalopelvic disproportion tests
Thesearedoneto detect contractedinlet if the head
isnot engagedin the last 3-4 weeksin a
primigravida.
• (1) Pinard’s method:
• Thepatient evacuates her bladder andrectum.
• The patient is placed in semi-sitting position
to bring the foetal axis perpendicular tothe
brim.
• Theleft hand pushesthe head downwards and
backwardsinto the pelvis while the fingers of the
right hand are put on the symphysis to detect
disproportion.
30. (2) Muller - Kerr’smethod:
• It is more valuable in detection of
the degreeof disproportion.
• Thepatient evacuatesher bladder and
rectum.
• Thepatient is placed in the dorsal
position.
• Theleft hand pushesthe head into the
pelvis and vaginal examination is done
by the right hand while its thumb is
placedover the symphysisto detect
disproportion.
Cephalopelvic disproportion tests
31. Degreesof Disproportion
1.Minor disproportion:
Theanterior surface of the head is in line with the
posterior surface of the symphysis.During labour the
headisengageddue to moulding andvaginaldelivery
canbe achieved.
2.Moderate disproportion 1st degree
disproportion):The anterior surface of the head is in
line with the anterior surface of the symphysis.V
aginal
delivery may or may not occur.
3. Marked disproportion 2nd degreedisproportion):
Thehead overrides the anterior surface ofthe
symphysis.Vaginaldelivery cannotoccur.
32. Degrees of Contracted Pelvis
1.Minor degree:Thetrue conjugate is9-10 cm.
It corresponds to minordisproportion.
2.Moderate degree: Thetrue conjugate is 8-9 cm.
It corresponds to moderatedisproportion.
3.Severedegree:Thetrue conjugate is 6-8 cm.
It corresponds to markeddisproportion.
4.Extremedegree:Thetrue conjugate islessthan
6 cm. Vaginaldelivery is impossible even after
craniotomy asthe bimastoid diameter (7.5 cm) is
not crushed.
33. Management
depends mainly
on the degree of
disproportion
Minor
vaginal delivery
Moderate
trial labor, if
failed caesarean
section.
Sever
caesarean section
Contracted pelvis
34. Trial of Labour
• It isaclinical test for the factors that cannot
be determined before start of labouras:
Efficiency of uterinecontractions.
Moulding of thehead.
Yielding of the pelvis and softtissues.
35. Procedure :
Trialiscarried out in ahospital where facilities
forC.Sis available.
Adequateanalgesia.
Nothing bymouth.
Avoidprematurerupture of membranesby:
rest in bed,
avoid high enema,
minimise vaginalexaminations.
Thepatient isleft for 2hoursin the 2ndstage
with good uterine contractions under close
supervision to the mother andfoetus
36. Indications of trial of labour:
1. Y
oungprimigravida of good
health.
2. Moderate disproportion.
3. Vertex presentation.
4. No contracted outlet
5. Averagesized baby
.
6. Vertexpresentation
37. Termination of trial oflabour:
Vaginal delivery: either spontaneously or
by forceps if the head is engaged.
Caesareansection if: failed trial of labour
i.e. the head did not engageor
complications occur during trial as
foetal distress or prolapsed pulsating cord
beforefull cervical dilatation.
38. Indications of caesarean section in
contracted pelvis
1. Moderate disproportion if trial of labour
is contraindicated or failed.
2. Marked disproportion.
3. Extremedisproportion whether the foetus is
living or dead.
4. Contracted outlet.
5. Contracted pelviswith other indicationsas;
I. elderly primigravida,
II. malpresentations, or
III. placenta praevia.
40. •Maternal:
Duringpregnancy:
1. Incarcerated retroverted graviduterus.
2. Malpresentations.
3. Pendulous abdomen.
4. Nonengagement.
5. Pyelonephritis especialy in high assimilation
pelvis due to more compression of the ureter.
Complications of ContractedPelvis
41. Complications of ContractedPelvis
During labour:
1. Inertia, slow cervical dilatation and
prolonged labour.
2. Premature rupture of membranes and
cord prolapse.
3. Obstructed labour andrupture uterus.
4. Necrotic genito-urinary fistula.
5. Injury topelvic joints or nervesfrom
difficult forceps delivery.
6. Postpartum haemorrhage.