MAL POSITIONS / MAL MAL POSITIONS / MAL PRESENTATIONSPRESENTATIONS

• Occiptio-posterior position 1 in 5 deliveriesOcciptio-posterior position 1 in 5 deliveries• Face presentation 1 in 500 deliveriesFace presentation 1 in 500 deliveries• Brow presentation 1 in 1000 deliveriesBrow presentation 1 in 1000 deliveries• Breech presentation 1-2 in 50 deliveriesBreech presentation 1-2 in 50 deliveries• Shoulder presentation 1 in 200 deliveriesShoulder presentation 1 in 200 deliveries• Unstable lie 1 in 350 deliveriesUnstable lie 1 in 350 deliveries

Occipito – posterior position..Occipito – posterior position..

In a vertex presentation when the occiput is In a vertex presentation when the occiput is placed posteriorly over the sacrum / sacro – placed posteriorly over the sacrum / sacro – iliac joint, it is called an occipito – posterior iliac joint, it is called an occipito – posterior position.position.

R.O.P. – Occiput on right sacro - iliac joint.L.O.P. – Occiput on left sacro – iliac joint.Direct occipito – posterior – occiput points towards sacrum.

LOP

Occipito – posterior is an abnormal position of the Occipito – posterior is an abnormal position of the vertex rather than an abnormal presentation. (In most vertex rather than an abnormal presentation. (In most of cases (90%) anterior rotation of occiput occurs.) of cases (90%) anterior rotation of occiput occurs.) But as the posterior position may give rise to But as the posterior position may give rise to Dystocia (abnormal labour & delivery), it is Dystocia (abnormal labour & delivery), it is associated with mal presentation.associated with mal presentation.

Incidence – upto 13% of all vertex presentation.Incidence – upto 13% of all vertex presentation. R.O.P. is 3 times more common than L.O.P.R.O.P. is 3 times more common than L.O.P.

WHY ??WHY ??--Dextro-rotation of the uterus favours Dextro-rotation of the uterus favours

occipito-posterior than right occipito-occipito-posterior than right occipito-anterior positionanterior position

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

-The left oblique diameter is reduced by the -The left oblique diameter is reduced by the presence of sigmoid colonpresence of sigmoid colon

Causes :- Causes :-

Not clear but factors abound – Not clear but factors abound – 1.1. CPD , CPD , Maternal kyphosisMaternal kyphosis2.2. Contracted pelvis:-50% or more occipito –posterior Contracted pelvis:-50% or more occipito –posterior

position is associated with either an anthropoid or android position is associated with either an anthropoid or android pelvis pelvis due to narrow fore-pelvisdue to narrow fore-pelvis..

2. Fetus – deflection of fetal head favours posterior position of 2. Fetus – deflection of fetal head favours posterior position of the vertex. Causes of deflection are –the vertex. Causes of deflection are –

a.a. High pelvic inclination.High pelvic inclination.

b.b. Placenta praevia, pelvic tumors.Placenta praevia, pelvic tumors.

3. Uterus – abnormal uterine contraction.3. Uterus – abnormal uterine contraction.

4. Pendulous abdomen esp. in multipara.4. Pendulous abdomen esp. in multipara.

Diagnosis: –Diagnosis: –

Inspection :-Inspection :-- Abdomen looks flat below the umbilicus. Abdomen looks flat below the umbilicus.

Palpation :-Palpation :-Fundal height :- corresponds with period of amenorrhoea.Fundal height :- corresponds with period of amenorrhoea.Fundal grip :- breech.Fundal grip :- breech.Lateral grip :-Foetal back is felt on rt. Flank of mother in in Lateral grip :-Foetal back is felt on rt. Flank of mother in in

ROP & in left flank in LOP.ROP & in left flank in LOP.Fetal limbs are felt easily as knob like structure anteriorly.Fetal limbs are felt easily as knob like structure anteriorly.Pelvic grip :-Head is not engaged.Pelvic grip :-Head is not engaged. -Cephalic prominance (sinciput) is not felt so prominent as -Cephalic prominance (sinciput) is not felt so prominent as

found in well flexed occipito – anterior.found in well flexed occipito – anterior. -In direct occipito – posterior the small sinciput is confused -In direct occipito – posterior the small sinciput is confused

with breech.with breech.

-Auscultation :- -Auscultation :- FHS is best heard in flank in direct occipito – posterior / R.O.P. but FHS is best heard in flank in direct occipito – posterior / R.O.P. but

difficult in L.O.P. difficult in L.O.P.

Vaginal examination :- Vaginal examination :- 1.1. Finding depends upon degree of flexion of head.Finding depends upon degree of flexion of head.2.2. Conformed dx. Is made during 2Conformed dx. Is made during 2ndnd stage of labour on rupture stage of labour on rupture

of membrane by:-of membrane by:- a. Sagittal suture:- occupies any of the oblique diameter of a. Sagittal suture:- occupies any of the oblique diameter of

pelvis.pelvis. b. posterior fontanelle :-felt near the sacro-iliac joint.b. posterior fontanelle :-felt near the sacro-iliac joint. c. anterior fontanelle :- felt near the ilio-pectineal eminence.c. anterior fontanelle :- felt near the ilio-pectineal eminence.

Mechanism of labour – Mechanism of labour – 1.1. Head engages through the right oblique diameter in R.O.P. & Head engages through the right oblique diameter in R.O.P. &

Left oblique diameter in L.O.P. Because of deflection Left oblique diameter in L.O.P. Because of deflection engagement is delayed. engagement is delayed.

2.2. In most of the cases (90%) – In most of the cases (90%) – a. flexion – due to good uterine contraction there is flexion of a. flexion – due to good uterine contraction there is flexion of

head.head. b. internal rotation of the head – occiput rotates to 135 degrees b. internal rotation of the head – occiput rotates to 135 degrees

anteriorly to lie behind the symphysis pubis, shoulder rotates anteriorly to lie behind the symphysis pubis, shoulder rotates to occupy right oblique diameter.to occupy right oblique diameter.

3. Further descent & delivery of the head occurs like occipito – 3. Further descent & delivery of the head occurs like occipito – anterior position. anterior position.

4. Birth of shoulders & trunk – is the same as that of occipito 4. Birth of shoulders & trunk – is the same as that of occipito anterior.anterior.

Fate of OPPFate of OPPOPP

Engaging diameter :- occipito-frontal 11.5cm or sub-occipitofrontal 10cm.

Favorable (90%)Unfavorable (10%)

3/8th rotation

occipit comes under symphysis pubis (rt/lt occipito anterior)

Normal vaginal delivery

Mild deflexion Moderate deflexion Severe deflexion

Occiput rotate by 1/8th circle

Deep transverse arrest

Non-rotation

Oblique posterior arrest

Occiput rotate posteriorly by 1/8th

POPP/ occipito-sacral position

Face to pubis delivery Arrest

Factors favouring long anterior rotation

(1) Well flexed head.     

(2) Good uterine contractions.              

(3) Roomy pelvis.

(4) Good pelvic floor.     

(5) No premature rupture of membranes.

 

Causes of failure of long anterior rotation:

(1) Deflexed head.                          

(2) Uterine inertia.

(3) Contracted pelvis: rotation of the head cannot easily occur in android pelvis due to projection of the ischial spines and convergence of the side walls.            

(4) Lax or rigid pelvic floor.

(5) Premature rupture of membranes or its rupture early in labour.

Management Management

During 1During 1stst stage:- stage:-

1.1. Early diagnosisEarly diagnosis

2.2. Fetal, maternal condition and pelvic Fetal, maternal condition and pelvic assessment should be done.assessment should be done.

3.3. Prevent rupture of membrane by bed Prevent rupture of membrane by bed rest in lt. lateral position.rest in lt. lateral position.

4.4. Partograph to be strictly maintain.Partograph to be strictly maintain.

5.5. Early c/s in contracted pelvis.Early c/s in contracted pelvis.

Second stage Second stage 2nd stage

p/v exam:- To see level of presenting part, degree of flexion, position, caput, moulding, cx.

Favorable (90%)Unfavorable (10%)

Ant. 3/8th rotation

occipit comes under symphysis pubis (rt/lt occipito anterior)

Normal vaginal delivery

Mild deflexion Moderate deflexion Severe deflexion

Occiput ant. rotate by 1/8th circle

Deep transverse arrest

Non-rotation

Oblique posterior arrest

Occiput rotate posteriorly by 1/8th

POPP/ occipito-sacral position

Management of DTAManagement of DTADTA or oblique posterior arrest

Assisted delivery

Pelvis adequate Inadequate pelvis

-Manual rotation of occiput to anterior position followed by forceps extraction- vacuum delivery- forceps rotation

Dead baby

Craniotomy C/S

Manual rotation and extraction by forceps:

 

Under general anaesthesia the following steps are done:

 

1-Disimpaction: the head is grasped bitemporally and pushed slightly upwards.

2-Flexion of the head.

3-Rotation of the occiput anteriorly by the right hand vaginally aided by,

- Rotation of the anterior shoulder abdominally towards the middle line by the left hand or an assistant.

4-- Fix the head abdominally by an assistant, apply forceps and extract it

POPPPOPPPOPP

Spontaneous face to pubis delivery

Arrest

Head above the ischial spine / big baby

C/S (best) Manual rotation + forceps

Adequate pelvis Inadequate pelvis Dead baby

Head below the spines

Forceps with deep episiotomy

C/SCraniotomy

Prognosis – Prognosis –

Increased maternal morbidity due to pronlonged labour Increased maternal morbidity due to pronlonged labour & increased incidence of operative delivery.& increased incidence of operative delivery.