Malposition Opp 3s2865

Malpositions and Malpresentations

Introduction  Baby presents itself in the mother’s pelvis in any

position other than the vertex presentation -

abnormal presentation, or malpresentation.  ‘Abnormal’ - because -higher risk of obstruction

and other birth complications than the vertex presentation.

Contd…

 The normal way for a baby to deliver -vertex with

the occiput lying anteriorly.  Cephalic presentation-if the occiput is not lateral

in early labour or anterior in advanced labour then a malposition exists. Contd…

 If the leading pole of the foetus is anything other

than the vertex, a malpresentation exists.  Malpositions and malpresentations present in

labour can proceed to normal during delivery.  More difficult labour is common  Operative delivery & risk is high for both.

Contd…

 Left and right occipito-anterior are the only

normal presentations and positions.  Malposition: occipito-posterior.  Malpresentations: anything except vertex. Contd…

 Malpresentations are

– Face presentation, – Brow presentation,

– Breech presentation, – Shoulder presentation,

– Cord presentation and – Complex presentations.

Malposition: OccipitoPosterior

1. Introduction  Most common type of malposition of the occiput.  A persistent occipitoposterior position (POP)

results from a failure of internal rotation prior to birth.  In Occipito-Posterior - The vertex is presenting,

but the occiput lies in the posterior rather than the anterior part of the pelvis.

2. Definition In a vertex presentation where

the

occiput

is

placed posteriorly over the sacro iliac t or directly over the sacrum, it is called an occipito posterior position

3. Incidence - 10% of all vertex presentations - Expected more during late pregnancy and much less

in late second stage of labour.

- Early in labour(10-20%)

- Late in labour(1-2%) Contd…

- ROP is 5 times more common than the LOP

- Dextro rotation of the uterus

- Presence of sigmoid colon on the left- Diminished left oblique diameter -disfavor LOP position.

- The right oblique diameter is slightly longer than the left one.

4. Types  ROP

 LOP  DOP  POP

 Primary: It occur late in pregnancy before the

onset of labour. It occur in association with anthropoid pelvis.  Secondary: It develops during labour and in association with android pelvis

ROP

LOP

4. Types  Primary: It occur late in pregnancy before the

onset of labour. It occur in association with anthropoid pelvis.  Secondary: It develops during labour and in

association with android pelvis

5. Causes  Not clear

 The shape of the pelvic inlet: (50-85%)

anthropoid and android pelvises are the most

common cause - due to narrow fore-pelvis & roomier hind pelvis  Others(15%)  High pelvic inclination

Contd…

 Abnormal uterine contraction  Maternal kyphosis: The convexity of the fetal

back fits with the concavity of the lumbar kyphosis.  Anterior insertion of the placenta  Fetal factors: Marked deflection of the fetal

head.

Contd…

 Reasons for deflexion of head

– High pelvic inclination – Attachment of the placenta on the anterior wall of the uterus – Primary brachy-cephaly Contd…

 Other causes of Malpresentation:

– Placenta praevia,

– Pelvic tumours, – Pendulous abdomen, – Polyhydramnios, – Multiple pregnancy. - Idiopathic(10-30%)

6. Risk factors for OP position at delivery include  Nulliparity  Maternal age greater than 35 years

 Obesity  African-American race  Previous OP delivery Contd…

6. Risk factors for OP position at delivery include  Decreased pelvic outlet capacity  Gestational age ≥41 weeks

 Birth weight ≥4000 g  Prolonged first and/or second stage of labor

7. Diagnosis  Antenatal diagnosis  Diagnosis during labour

 Imaging

Contd…

A. Antenatal diagnosis i.

Listen to the mother

ii. Abdominal

examination

–

Inspection

Palpation and Auscultation iii. Antenatal preparation

Contd…

i. Listen to the mother  Complain of backache  She may feel that her baby’s bottom is very

high up against her ribs.  Reports - feeling movements across both sides

of her abdomen. Contd…

ii. Abdominal examination – Inspection Palpation and Auscultation Inspection  The abdomen looks flat, below the umbilicus.  saucer-shaped depression at or just below the

umbilicus-‘dip’ between the head and the lower limbs of the fetus. Contd…

a. Inspection  The

outline

created

by

the

high, unengaged head

can

look

like

a

full

bladder.

Comparison of abnormal contour in posterior (1) and anterior positions (2) of the occiput

b. Palpation ON PALPATION:

- The breech is easily palpated at the fundus, - The back is difficult to palpate as it is out of

maternal side and almost adjacent to the maternal spine. - Limbs can be felt on both side of midline Contd…

b. Palpation - High head – reason for non engagement in Primi

gravida

-

large

presenting

diameter,

the

occipitofrontal (11.5cm) The occiput and sinciput are on the same level. Flexion allows the engagement of the suboccipitofrontal diameter (10cm). Contd…

Engaging diameter of a deflexed head, OF 13.5cm

Flexion with Descent of the head

b. Palpation  Umbilical grip: The findings are:

1.The fetal limbs are more easily felt near the midline on either side. 2.The fetal back is felt away from the midline on the flank and often difficult to outline clearly. 3.The anterior shoulder lies far away from the midline.

Contd…

b. Palpation  Umbilical grip: The findings are:

1.The fetal limbs are more easily felt near the midline on either side. 2.The fetal back is felt away from the midline on the flank and often difficult to outline clearly. 3.The anterior shoulder lies far away from the midline.

Contd…

b. Palpation  Pelvic grips: The findings are:

1. The head is not encaged. 2. The cephalic prominence (Sinciput) is not felt as prominent as found in well flexed occipitoanterior. In direct occipito-posterior, the small sinciput is confused with breech. Contd…

b. Palpation  The cause of the deflexion

– Is a straightening of the fetal spine against the lumbar curve of the maternal spine. – This makes the fetus straighten its neck and adopt a more erect attitude.

ON AUSCULTATION:

- F.H.S can be heard at

midline. - Sometime f.H.S can be heard more easily at the flank on the same side of the back. - Difficult to locate specially in lop

iii. Antenatal preparation  Active changes of maternal posture.  Mother adopting a knee–chest position several

times a day - temporary rotation of the fetus to an anterior position - short-term effect upon fetal presentation.

B. Diagnosis during labour  Head is high  Non engagement of head

 May complain of continuous and severe

backache worsening with contractions

B. Diagnosis during labour  Large

and

irregularly

shaped

presenting

circumference - membranes tend to rupture spontaneously at an early stage of labour  Contractions may be incoordinate.

B. Diagnosis during labour  Good contractions but slow descending of the

head.  Strong desire to push early in labour because the

occiput is pressing on the rectum.

Presenting dimensions of a deflexed head

Vaginal examination  The findings will depend upon the degree of

flexion of the head.  Anterior fontanelle in the anterior part of the

pelvis - difficult if caput succedaneum is present.  The direction of the sagittal suture and location

of

the

diagnosis.

posterior

fontanelle

confirms

the

Contd…

 The findings in early labour are:  Elongated bag of membranes - rupture during

examination.  The sagittal suture occupies any of the oblique

diameters of the pelvis.

 Posterior fontanelle is felt near the sacro iliac

t.  The anterior fontanelle is felt more easily

because of the deflexion of the head and at times, is felt at a lower level than the posterior one.

 In late labour  diagnosis is often difficult - caput formation

which obliterates the sutures and fontanelles.  In such cases, the ear is to be located and the

unfolded pinna points towards the occiput.  Simultaneous assessment of the pelvis should be

done.

c. Imaging  Ultrasonagraphy is rarely done.  It is helpful to know the descent, attitude of

the head and its relation to the pelvic walls (position).

8. Mechanism of (labour) Right occipitoposterior position (long rotation)  The head encages through the

– right oblique diameter in ROP and – left oblique in LOP.  The encaging transverse diameter of the head is

biparietal (9.5cm) Contd…

8. Mechanism of (labour) Right occipitoposterior position (long rotation)  Antero-posterior diameter is either

– Suboccipito-frontal (10cm) or

– Occipito-frontal

(11.5cm)

(deflexion

engagement is delayed).  In favorable circumstances of OPP - mechanism

is possible.

Contd…

Fetal Description/Criteria:

The lie is longitudinal • The attitude of the head is deflexed

• The presentation is vertex • The position is right occipitoposterior

• The denominator is the occiput Contd…

Fetal Description/Criteria:

The presenting part is the middle or anterior area of the left parietal bone

The occipitofrontal diameter, 11.5cm, lies in the right oblique diameter of the pelvic brim.

The occiput points to the right sacroiliac t and the sinciput to the left iliopectineal eminence. Contd…

Mechanism of labour  The main movements are: – Flexion

– Internal rotation of the head – Crowning

– Extension – Restitution

– Internal rotation of the shoulders – External rotation of the head

– Lateral flexion

Crowning: Occiput escape under the pubic arch and the head is said to be crown

Alternative mechanism in favorable situation (uncommon)  If the shoulders fail to follow the anterior rotation

of the occiput,  The neck sustains a torsion and the shoulders

remain static in the left oblique diameter in ROP

and in the right oblique diameter in LOP.

 In such cases  Restitution occurs 3/8th of a circle and

 External rotation occurs through 1/8th of a circle

in the opposite direction of restitution.  However the mechanism is quite unlikely.

 In OP Presentation

Favorable circumstances 90%

Unfavorable circumstances 10%

In unfavorable circumstances of OPP  In Certain circumstances

The occiput fails to rotate as described

previously.

 The causes of faulty rotation

Deflexion of the head, Weak uterine contraction, Faulty shape of the pelvis - flat sacrum, prominent ischial spines or convergent side walls and weak pelvic floor muscles. Big baby and immobility of the fetal trunk The drainage of liquor amnii.

Incomplete forward rotation

Results in Deep transverse arrest

Sinciput & occiput touch the pelvic floor simultaneously

Oblique posterior arrest

Malrotation - Sinciput anterior rotation - occiput to the sacral hollow Occipito- sacral position

Favorable circumstances

Face to pubis

Unfavorable circumstances

Occipito-sacral arrest

Mechanism of Face to Pubis delivery  Further descent occurs  Flexion occurs

 Restitution  External rotation

Persistent occipito-posterior  Abnormal mechanism of the occipito- posterior

position.  Delivery - spontaneously as face –to-pubis or

occipito- sacral arrest.

Deflexed head, Faulty shape of pelvis, Weak pelvic floor muscles, Big baby, Immobility of fetal trunk, Drainage of AF

Incomplete forward rotation

Sinciput & occiput touch the pelvic floor simultaneously

Malrotation - Sinciput anterior rotation - occiput to the sacral hollow

COURSE OF LABOUR/ CARE IN LABOUR  Course of events in labour are modified  Longer first and second stage

 Painful labour  The deflexed head – not fit well onto the cervix -

does not produce optimal stimulation for uterine contractions

First stage  Tendency to delay means longer time of first

stage.  Causes are

1. Delay in engagement

Persistence of deflexion of the head

Driving force – fetal axis – not in

alignment

2. Membrane status -

Deflexed head - cannot fit well in spherical lower segment - loss of ball valve action - uterine contraction - EROM and drainage of liquor.

3. Uterine contraction-

ill fitting in the LUS -lack of stimulus for uterine contraction- results slow dilatation of the cervix. Pressure on the rectum by wide occiput - premature desire of bearing down effort in 1st stage. Exhaustion of client.

The woman may experience  Severe and unremitting backache, causes tiring -

very demoralizing because of slow progress.  Midwife essential for mother and her

partner to cope with the labour.  The

all-fours

discomfort.

position

may

relieve

some

 Prolonged

labour

-

prevent

the

mother’s

dehydration or ketosis.  Incoordinate

uterine

action

or

ineffective

contractions – correct an oxytocin infusion.  The woman may experience a strong urge to

push before full dilation – causes cervix edema – delay onset of 2nd stage.

 The urge to push eased by - change in position,

use of breathing techniques or inhalational analgesia - enhances relaxation.  Partner/midwife can assist throughout labour

with massage, physical and suggestions

for alternative methods of pain relief.  Pain control methods.

Second stage  Delayed 2nd stage - long internal rotation or

malrotation / arrest of the head.  This may happen in android pelvis or in mid

pelvic or in mid pelvic contraction.  If felt uncared - arrest of the head may lead to

obstructed labour.

 Confirm full dilatation of the cervix -

moulding and caput succedaneum may

bring the vertex into view.  Onset of 2nd stage – no visible head -

encourage the woman to remain uprightshorten the length of the second stage and may reduce the need for operative delivery.

Third stage  Increased incidence of

Postpartum hemorrhage and

Trauma of the genital tract

MODE OF DELIVERY  Long anterior rotation of the occiput - SVD or

AVD.  Short posterior rotation - SVD or AVD and

perineal injuries  Non- rotation or short anterior rotation – SVD.

Uncared - prolonged and obstructed labour. Trauma to the genital tract

MODE OF DELIVERY  Moulding - compression of the OF diameter with

elongation

of

the

vault.

Frontal

bones

displacement beneath the parietal bones tentorial tear.

MODE OF DELIVERY  Prognosis

Maternal morbidity (4 out of 5 cases no trouble),

Incidental to prolonged labour and operative delivery.

Increased perinatal morbidity and mortality asphyxia or trauma during vaginal operative delivery.

MANAGEMENT OF LABOUR  Principle in the management of the OPP are

1) Early diagnosis,

2) Strict vigilance with watchful expectancy 3) Judicious and timely interference, if necessary.

 Diagnosis and evaluation:  Fetal back on the flank - F.H.S not easily

located,  Early ROM should arouse suspicion.  Internal examination is confirmatory.  Overall assessment of the client and  The pelvic assessment is mandatory.

 Early Caesarean Section

OPP is not an indication of caesarean section.  CS for Pelvic inadequacy or its unfavorable

configuration,  Obstetric complications - pre-eclampsia, post

caesarean pregnancy, big baby usually need caesarean section.

 First stage  Allow for normal labour in uncomplicated cases.  The following are the special instructions:  Anticipating prolonged labour- IV RL.

 Judge progress of labour  Observe for a triad - Weak pain, persistence of

deflexion and non-rotation of the occiput  Indication of caesarean section

 Judge Progress of Labour (a) Progressive descent of the head

(b) Rotation of the back and the anterior shoulder

towards the midline (c) Increasing flexion of the head (d) Position of the sagittal suture on vaginal

examination and (e) Cervical dilatation.

 Weak pain, persistence of deflexion and non-

rotation of the occiput are the triad –

coexistent - oxytocin infusion for augmentation of labour.  Indication of caesarean section

(a) Arrest of labour (failure of rotation)

(b) Incoordinated uterine action (c) Fetal distress.

 Second Stage  In majority anterior rotation of the occiput is

completed and  The delivery is either spontaneous or

 By low forceps or ventouse.

 Second stage: In minority

(Unrotated & Malrotated)  Good fetal and maternal conditions - a watchful

expectancy.  In occipito-sacral position, spontaneous delivery

as face- to pubis may occur. In such cases, • Proper conduction of delivery and • Liberal episiotomy- to prevent complete perineal tear.

 Third Stage  Prolongation of labour - Tendency of PPH

 Prophylactic IV ergometrine 0.25 mg - delivery

of anterior shoulder.  Meticulous inspection of the cervix and lower

genital tract to detect any injury.

Arrested Occipito-posterior Position  Good uterine contractions for about 1/2-1 hour +

full dilatation of the cervix = if no progress interference is indicated.  Once more to be assessed - abdominal and

vaginal before suitable method of interference.  Types of arrested OPP – transverse, oblique,

sacral

 Per abdomen: Assess:

(1) Size of the baby (2) Engagement of the head (3) Amount of liquor

(4) F.H.S.

 Vaginal examination: Note

(1)Station of the head

(2) Position of the sagittal suture and the occiput (3) Degree of deflexion of the head

(4) Degree of moulding and caput formation (5) Assessment of the pelvis at and below the level of obstruction.

ARREST IN OCCIPITOTRNSVERSE OR OBLIQUE O. P. POSITION  Ventouse (Vacuum extraction)  Alternative methods:

– Manual rotation followed extraction. – Forceps rotation and extraction – Caesarean section – Craniotomy

by

forceps

OCCIPITO-SACRAL ARREST

 Head engaged

 Occiput descends below the ischial spines,  Forceps application in unrotated head followed

by

extraction

as

face-to-pubis

-

effective

procedure.  Liberal mediolateral episiotomy.  If occiput remains at or above the level of ischial

spines - caesarean section.

DEEP TRANSVERSE ARREST (DTA)  The head is deep into the cavity  Sagittal suture - transverse bispinous diameter

 No progress in descent of the head even after 1/2-

1 hour following full dilation of the cervix.

 Arrest in occipito-transverse position - end result

of incomplete anterior rotation (1/8th of circle) of

oblique occipito-posterior position. or it may be due to  Non-rotation of the commonly primary occipito-

transverse position of normal mechanism of labour.

Causes of DTA (a) Faulty pelvic architecture (b) Deflexion of the head (c) Weak uterine contraction (d) Laxity of the pelvic floor muscles.

Diagnosis of DTA (a) The head is engaged (b) The sagittal suture lies in the transverse

bispinous diameter (c) Anterior fontanelle is palpable

(d) Faulty pelvic architecture

Management  The fetal condition and pelvic assessment -

guide as to the line of management  Vaginal delivery is found safe (1) Ventouse- ideal (2) Manual rotation and application of forceps

Management (3) Forceps rotation and delivery - Kielland / expert (4) Vaginal delivery is not safe - with big baby and or inadequate pelvis - Caesarean Section (5) Craniotomy in dead baby.

MANUAL ROTATION  Whole hand method or With half hand method  Patient - in lithotomy position and GA  Strict aseptic technique  Catheterize the bladder  Vaginal examination and detect the direction of

occiput – if caput seek help of unfolded pinna

MANUAL ROTATION Whole hand method  Step- I: Gripping of the head  Step-II: Rotation of the head

 Step-III: Application of the forceps

Step- I: Gripping of the head  R.O.P. or R.O.T. - Left hand and  L.O.P. or L.O.T. - Right hand  Separate the labia by two fingers  Introduce the corresponding hand into the vagina

in a cone shaped manner.

Step- I: Gripping of the head  Occipito-transverse

position - the four fingers are pushed in the sacral

hollow to be placed over the posterior parietal bone and

the thumb is placed over the anterior parietal bone.

Step- I: Gripping of the head  In

oblique

posterior

position - the four fingers of partially supinated hand

are placed over the occiput and the thumb is placed

over the sinciput.

Step-II: Rotation of the head  Slight

dis-impaction

needed for good grip.  By

a movement of

pronation of the hand, rotate the head to bring

the

occiput

along

route.

the

anterior shortest

Step-II: Rotation of the head  Simultaneously, the back of the fetus is rotated

by the external hand from the flank to the midline - essential prerequisite.  A little over rotation is desirable anticipating

slight recurrence of malposition before the application of forceps.

Step-III: Application of the forceps

 If right hand is placed on the left side of the

pelvis introduce left blade.  In left hand use - place right side of the pelvis.

 While introducing the blades, - assistant fixes the

head by suprapubic pressure - first pelvic grip.  As it is a mid forceps application, axis traction

device should be used.

Difficulties and dangers 1) Failure to grip the head

2) Failure to dislodge the head from the impacted position

3) Inadequate anesthesia 4) Wrong case selection.  Dangers- accidental slipping of the head above the

pelvic brim and prolapsed of the cord.

HALF HAND METHOD  Four fingers are only introduced in to the vagina.  Advantages i) Less space is required and ii) Less chance to displacement of the head

Steps  The rotation is done only by using the right hand.  With four fingers tangential pressure is applied

on the head at the level of diameter of engagement.  Pressure is applied on the side and the parietal

eminence of the head.

Steps  In R.O.P. or R.O.T. position the fingers are

placed anterior to the head and the pressure is applied by the ulnar border of the hand.  In L.O.P. or L.O.T. position, the fingers are

placed posteriorly and the pressure is applied intermittently till the occiput is placed behind the symphysis pubis.

Complications  PROM in early labour.

 Cord presentation and prolapse  Prolonged & obstructed labour  Maternal, neonatal trauma – rupture of uterus, PPH,

Puerperal sepsis & Cerebral hemorrhage  Increased incidence of perinatal mortality.  Increased incidence of instrumental and operative

delivery.

Possible Nursing Diagnosis  Acute pain related to

progress of labor.  Anxiety RT slow progress of labour  Alteration in fetal tissue perfusion related to maternal position, epidural, oxytocin, rupture of membranes

 Potential for infection

related to rupture of membranes

 Bibliography - Fraser

and

midwives.14th

Cooper.

Myles

edition.churchill

textbook

of

livingstone

publication.philadelphia2007. page no 551-557 - Dutta D.C. Text book of obstetrics.6th edition.

New central book publication. kolkata 2006. page no 365-374