Cephalopelvic disproportion (CPD) refers to a disparity between the fetal head size and the mother's pelvic size that can impact labor and delivery. It is defined as the essential diameters of the pelvis being shortened by at least 0.5 cm. CPD can be caused by conditions like rickets, osteomalacia, or injuries that impact pelvic development. It increases risks during labor like prolonged labor, operative delivery, maternal injuries, and fetal hazards. Management options include preterm induction, elective c-section, or a trial of labor depending on the individual case.

1. CEPHALOPELVICCEPHALOPELVIC
DISPRAPORTIONDISPRAPORTION

2. DEFINITIONDEFINITION
““Anatomically, contracted pelvis is defined asAnatomically, contracted pelvis is defined as
one where the essential diameters of one or moreone where the essential diameters of one or more
planes are shortened by 0.5 cm.”planes are shortened by 0.5 cm.”
““obstetric definition which states thatobstetric definition which states that
alteration in the size and/or shape of the pelvis ofalteration in the size and/or shape of the pelvis of
sufficient degree so as to alter the normalsufficient degree so as to alter the normal
mechanism of labour in an average size baby.”mechanism of labour in an average size baby.”

3. VARIATIONS OF FEMALE PELVISVARIATIONS OF FEMALE PELVIS
on the basis of the shape of the inlet, the femaleon the basis of the shape of the inlet, the female
pelvis is divided into four parent types:pelvis is divided into four parent types:
• Gynaecoid (50%)Gynaecoid (50%)
• Anthropoid (20%)Anthropoid (20%)
• Android (20%)Android (20%)
• Platypelloid (5%)Platypelloid (5%)

5. ETIOLOGYETIOLOGY
• Severe malnutrition, Rickets, Osteomalacia, BoneSevere malnutrition, Rickets, Osteomalacia, Bone
tuberculosis.tuberculosis.
• Nutritional and environmental defects:Nutritional and environmental defects:
- minor variation- minor variation
- major- major
• Diseases or injuriesDiseases or injuries
• Development defects:Development defects:

6. • RACHITIC FLAT PELVIS:RACHITIC FLAT PELVIS:
- Early childhood- Early childhood
- bone remains soft and unossified- bone remains soft and unossified
- inlet: sacral promontory downward & forward- reniform- inlet: sacral promontory downward & forward- reniform
shape.shape.
- cavity: sacrum is flat & tilted backwards- cavity: sacrum is flat & tilted backwards
- outlet: widening of transverse diameter- outlet: widening of transverse diameter
• OSTEOMALACIC PELVIS:OSTEOMALACIC PELVIS:
- calcium & vitamin D deficiency- calcium & vitamin D deficiency
- soften bones and bends according to pressure- soften bones and bends according to pressure
- sacral promontory downward & forward- sacral promontory downward & forward
- scrum is shortened, pubic arch narrowed and coccyx- scrum is shortened, pubic arch narrowed and coccyx
pushed downwardspushed downwards

7. • NAEGELE’S PELVIS:NAEGELE’S PELVIS:
- arrested development of one ala- arrested development of one ala
• SCOLIOTIC PELVIS:SCOLIOTIC PELVIS:
- oblique diameter shortened- oblique diameter shortened
• ROBERT’S PELVIS: (TRANSVERSELYROBERT’S PELVIS: (TRANSVERSELY
CONTRACTED)CONTRACTED)
- rare- rare
- ala of both side absent- ala of both side absent
- sacrum fused with innominate bone- sacrum fused with innominate bone
- LSCS- LSCS
• KYPHOTIC PELVISKYPHOTIC PELVIS

8. CEPHALOPELVIC DISPRAPORTIONCEPHALOPELVIC DISPRAPORTION
““ The disparity in the relationThe disparity in the relation
between the head and pelvis isbetween the head and pelvis is
called CPD.”called CPD.”

9. DIAGNOSISDIAGNOSIS
• Clinical:Clinical:
- abdominal method- abdominal method
- abdomino-vaginal (Muller-Munro kerr)- abdomino-vaginal (Muller-Munro kerr)
• Imaging pelvimetryImaging pelvimetry
• Cephalometry : accurateCephalometry : accurate
- ultrsound- ultrsound
- MRI: pelvic capacity, fetal size,fetal head- MRI: pelvic capacity, fetal size,fetal head
volume, pelvic soft tissuesvolume, pelvic soft tissues
- X-ray- X-ray

10. EFFECTSEFFECTS
• Pregnancy (not much)Pregnancy (not much)
- incarceration of retroverted pelvis- incarceration of retroverted pelvis
- pendulous abdomen- pendulous abdomen
- malpresentation- malpresentation
• Labour:Labour:
- risk early rupture of membranes- risk early rupture of membranes
- cord prolapse- cord prolapse
- cervical dilatation slow- cervical dilatation slow
- prolonged labour- prolonged labour
- operative interference, shock, PPH and sepsis.- operative interference, shock, PPH and sepsis.
• Maternal injuriesMaternal injuries
• Fetal hazards : trauma and asphyxiaFetal hazards : trauma and asphyxia

11. MANAGEMENTMANAGEMENT
• Preterm induction of labourPreterm induction of labour
• Elective caesarean section at termElective caesarean section at term
• Trial labourTrial labour