Contracted Pelvis by KABERA Rene

CONTRACTED PELVIS

KABERA René,MD Resident- PGY II Ruhengeri Hospital Family and Community Medicine National University of Rwanda

Plan

� Introduction

� Definition

� Types of Pelvis

� Risk factors

� Diagnosis

� Management

� References

10/5/2010 Contracted Pelvis

Introduction

Knowledge of the shape and dimensions of the

normal female pelvis is essential for a proper

understanding of the second stage of labour and its

abnormalities since the body pelvis is an important

component which determines the birth canal

structure.


Definition

� Anatomical definition: It is a pelvis 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

one or more of its diameters is reduced so

that it interferes with the normal mechanism

of labour.


Major types of pelvis

Anthrapoid Android

Gynecoid

Platypelloid 10/5/2010 Contracted Pelvis

Risk factors

� Factors influencing the size and shape of the pelvis

� Developmental factor: hereditary or congenital.

� Racial factor.

� Nutritional factor: malnutrition results in small pelvis.

� Sexual factor: as excessive androgen may produce android pelvis.

� Metabolic factor: as rickets and osteomalacia.

� Trauma, diseases or tumors of the bony pelvis, legs or spines.


Diagnosis

History

� Trauma or diseases: of the pelvis, spines or

lower limbs.

� Bad obstetric history: e.g. prolonged labour

ended by difficulty; forceps, caesarean

section or still birth.


Diagnosis

Examination

General examination

� Abnormal gait.

� Stature: women < 150 cm.

Abdominal examination

� Pendolous abdomen in primigravida.

� Non engagement in last 3-4 wks of pregnancy

in primigravida.


Diagnosis

Pelvimetry

� External pelvimetry is of little value as it measures diameters of the false pelvis.

� Internal pelvimetry (done by per vagina exam)

� The inlet:

� Palpation of the forepelvis (pelvic brim): V-shaped depression.

� Diagonal conjugate: <11.5 cm (not used if the head is engaged).


Forepelvis

Diagnosis

Diagonal conjugate 10/5/2010 Contracted Pelvis

Diagnosis

� The outlet:

� Bituberous diameter : ≤8 cm

� Mobility of the coccyx: fixed


Management

The true

conjugate

Bituberous

diameter

Decision

> 9 > 8 cm Vaginal delivery

8-9 cm > 8 cm Trial of labour

8-9 cm ≤ 8 cm C-section

< 8 cm > or < 8cm C-section

N.B: The fetal measurements must be considered!!! 10/5/2010 Contracted Pelvis

References

� Geneva Foundation for Medical Education

and Research, Contracted Pelvis, Obstetrics

Simplified - Diaa M.EI-Mowafi.2009

� Williams Obstetrics .Section IV. Labor and

Delivery. Chapter 20. Dystocia: Abnormal

Labor, 22nd ed. 2005.

� Current Obstetrics and Gynecologic diagnosis

and treatment. Section III Pregnancy at risk.

Abnormalities of the passage, 9th ed. 2003.


� Thank you


Documents

Contracted Pelvis by KABERA Rene