Contracted pelvis, or cephalopelvic disproportion (CPD), occurs when the baby's head is too large to pass through the mother's pelvis during birth. CPD can be caused by a large baby, a small pelvis, or abnormal fetal positioning. A contracted pelvis may result from developmental factors, malnutrition, trauma, or diseases affecting bone development like rickets. Complications of CPD include prolonged labor, obstructed labor, rupture of the uterus, maternal and fetal injury, and increased risk of c-section. Management depends on the degree of disproportion, with c-section recommended for severe or extreme disproportion.

1. CEPHALO PELVIC
DISPROPORTION
(CPD)

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)
2. Abnormal fetal positions
3. Contracted pelvis
4. Abnormally shaped pelvis

5. Contracted
Pelvis

6. Contracted
Pelvis
Definition:
• Anatomical definition: It is apelvis in
which one or more of its diameters is
reduced below the normal by one or
more centimeters.
• Obstetric definition: It is a pelvis in
which its size & shape is sufficiently
abnormal that interfere with vaginal
deliveryof normal size fetus

7. Factors influencing the size and shape
of the pelvis:
1. Developmental factor: hereditaryor
congenital.
2. Nutritional factor: malnutrition results in
small pelvis.
3. Sexual factor: asexcessiveandrogenmay
produce android pelvis.
4. Metabolic factor: asrickets andosteomalacia.
5. Trauma, diseasesor tumours of thebony
pelvis, legs orspines.

8. Etiology of Contracted Pelvis
Causes in the pelvis
Developmental (congenital)
1. Small gynaecoid pelvis (generally contracted pelvis).
2. Small androidpelvis.
3. Small anthropoidpelvis
4. Small platypelloid pelvis (simple flat pelvis)

9. 5Naegele’s pelvis: absence of one
sacral ala
6Robert’s pelvis: absence of both
sacralalae.
7High assimilation pelvis: The sacrum
is composed of 6 vertebrae.
8Low assimilation pelvis: The sacrum
is composed of 4 vertebrae.
9 Split pelvis: splitted symphysispubis

10. • Causes in the pelvis
• Metabolic:
- Rickets.
- Osteomalacia (triradiate pelvicbrim).
• Traumatic: asfractures.
• Neoplastic: asosteoma.
• Infection :TB

11. Causes in the spine
• Lumbar kyphosis
• Lumbarscoliosis
• Spondylolisthesis:
The 5th lumbar vertebra with the above vertebral
column is pushed forward while the promontory is
pushed backwards and the tip of the sacrum is
pushed forwards leading to outlet contraction.

12. Causes in the lower limbs
• Dislocation of one orboth femurs.
• Atrophy of one or both lowerlimbs.

13. Pelvis
• History
• Rickets:isexpectedif there isahistory of
delayed walking and dentition.
• Traumaor diseases:of the pelvis, spinesor
lower limbs.
• Badobstetric history: e.g. prolonged labour
ended by:
 difficult forceps
 caesarean sectionor
 still birth.

14. •Examination
• Generalexamination:
 Gait:abnormal gait suggestingabnormalities in
the pelvis, spinesor lowerlimbs.
 Height: women with lessthan 150cmheight
usualy havecontractedpelvis.
 Spinesandlower limbs: mayhaveadiseaseor
lesion.( kyphosis,…)
Pelvis

15. General
examination:
Manifestations of rickets as:
 square head
 pigeon chest
 bowlegs.
Dystocia dystrophia syndrome: the
woman is
*short,obese, subfertile, has android pelvis.
Pelvis

16. Abdominal examination:
Non engagement of thehead:
in thelast 3-4 weeks inprimigravida.
 Pendulousabdomen:
in aprimigravida.
 Malpresentations:
are morecommon.
Pelvis

17. • Pelvimetry :
It is assessment of the pelvic diameters andcapacity
done at 38-39weeks.It includes:
1. Clinical pelvimetry:
 Internal pelvimetryfor:
 inlet
 cavity,and
 outlet.
 External pelvimetryfor:
 inlet and
 outlet.
Pelvis

18. •Pelvimetry:
2.Imagingpelvimetry:
 X-ray.
 Computed tomography(CT).
 Magnetic resonanceimaging (MRI).
• N.B. CTandMRI are recent and accurate but
expensiveandnot alwaysavailablesotheyare
not in commonuse.
Diagnosis ofContracted
Pelvis

20. External pelvimetry
• Thom’s, Jarcho’sor crossing
pelvimeter can be used for
externalpelvimetry.
Interspinous diameter
(25cm): between the
anterior superior iliac
spines.
Intercrestal diameter (28
cm): betweenthe most far
points on the outer borders of
the iliaccrests.
Externalconjugate (20cm).
Bituberous diameter
(11cm)

22. Radiological pelvimetry
• Lateral view:
 Thepatient standswith the X-ray tube on one
side andthe film cassetteon the opposite side.
 it shows
 the anteroposterior diameters of the pelvis,
angleof 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 backwards so that the plane of the
pelvic brim becomes parallel to thefilm.
• Outlet view: Thepatient sitson the film
cassetteand leans forwards.

23. Cephalometry
• Ultrasonography: isthe safeaccurateand
easymethod and candetect:
The biparietal diameter(BPD)
 The occipito-frontaldiameter.
Thecircumferenceof thehead.
• Radiology (X-ray: isdifficult to interpret.

24. Cephalopelvicdisproportiontests
Thesearedoneto detect contractedinlet if the head
is not engagedin the last 3-4 weeksin a
primigravida.
• (1) Pinard’smethod:
• Thepatient evacuatesher bladder andrectum.
• The patient is placed in semi-sitting
position to bring the foetal axis
perpendicular to the brim.
• The left hand pushes the head downwards
and backwardsinto the pelviswhile the
fingersof the right hand are put on the
symphysisto detect disproportion.

25. (2) Muller - Kerr’s method:
• It ismorevaluablein detectionof
the degreeof disproportion.
• Thepatient evacuatesher bladder and
rectum.
• Thepatient isplacedin the dorsal
position.
• Theleft handpushesthe headinto the
pelvis and vaginal examination is done
by the right hand while its thumb is
placed over the symphysisto detect
disproportion.
Cephalopelvicdisproportiontests

26. Degrees ofDisproportion
1.Minor disproportion:
The anterior surface of the head is in line with the
posterior surfaceof the symphysis.During labour the
headisengageddue to moulding andvaginal
delivery can beachieved.
2.Moderate disproportion 1st degree
disproportion:The anterior surface of the head is in
line with the anterior surfaceof the symphysis.Vaginal
delivery mayor maynot occur.
3. Marked disproportion 2nddegreedisproportion):
Theheadoverrides the anterior surfaceof the
symphysis.Vaginal delivery cannot occur.

27. Degrees of ContractedPelvis
1.Minor degree:Thetrue conjugate is9-10 cm.
It corresponds to minordisproportion.
2.Moderate degree:Thetrue conjugateis8-9 cm.
It corresponds to moderatedisproportion.
3.Severedegree:Thetrue conjugateis 6-8 cm.
It corresponds to markeddisproportion.
4.Extremedegree:Thetrue conjugate islessthan
6 cm. Vaginaldelivery is impossible even after
craniotomy asthebimastoid diameter (7.5 cm) is
not crushed.

28. Management
depends mainly
on the degree of
disproportion
Minor
vaginal delivery
Moderate
trial labor, if
failed caesarean
section.
Sever
caesarean section
Contracted pelvis

29. Trial of Labour
• It isaclinical test for the factors that cannot
be determined before start oflabour as:
 Efficiency of uterinecontractions.
 Moulding of thehead.
 Yieldingof the pelvis andsofttissues.

30. Procedure :
 Trial is carried out in ahospital where facilities for
C.Sis available.
 Adequate analgesia.
 Nothing bymouth.
 Avoid premature rupture of membranesby:
 rest in bed,
 avoid high enema,
 minimise vaginalexaminations.
 Thepatient is left for 2 hours in the 2nd stage with
good uterine contractions under close supervision
to the mother andfoetus

31. Indications of trial of labour:
1. Youngprimigravida ofgood health.
2. Moderate disproportion.
3. Vertexpresentation.
4. Average sizedbaby

32. Termination of trial oflabour:
 Vaginaldelivery: either spontaneouslyor
by forceps if the head isengaged.
 Caesareansection if: failed trial oflabour
i.e. the head did notengage or
complications occur during trialas
foetal distress or prolapsed pulsatingcord
before full cervicaldilatation.

33. Indications of caesarean section in
contracted pelvis
1. Moderate disproportion if trial of labour is
contraindicated or failed.
2. Marked disproportion.
3. Extreme disproportion whether the foetusis
living or dead.
4. Contracted pelvis with otherindications as;
I. elderly primigravida,
II. malpresentations, or
III. placenta praevia.

34. Complications
Maternal Fetal
During
pregnancy:
↑retroverted
gravid uterus.
Malpresentations.
Pendulous
abdomen
Nonengagement.
Pyelonephritis
due to more
compression of the
ureter.
During labour:
Slow cervical
dilatation and
prolonged labour.
PROM and cord
prolapse.
Obstructed labour
and rupture uterus.
Injury to pelvic
joints or nerves from
difficult forceps
delivery.
Postpartum
hemorrhage.
 Intracranial
hemorrhage.
 Asphyxia.
 Fracture skull.
 Nerve injuries.
 Intra-amniotic
infection
Contracted pelvis

35. •Maternal:
Duringpregnancy:
1. Incarcerated retroverted graviduterus.
2. Malpresentations.
3. Pendulousabdomen.
4. Nonengagement.
5. Pyelonephritis especial y in high assimilation
pelvis dueto more compressionof the ureter.
Complications of ContractedPelvis

36. Complications of Contracted
Pelvis
Duringlabour:
1. Inertia, slow cervical dilatationand
prolonged labour.
2. Premature rupture of membranesand
cord prolapse.
3. Obstructed labour andrupture uterus.
4. Necrotic genito-urinaryfistula.
5. Injury topelvic joints or nervesfrom
difficult forcepsdelivery.
6. Postpartum haemorrhage.

37. • Foetal:
1. Intracranial
haemorrhage.
2. Asphyxia.
3. Fractureskull.
4. Nerveinjuries.
5. Intra-amniotic infection.
Complications of Contracted
Pelvis