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									         MAL POSITIONS / MAL
•   Occiptio-posterior position     1 in 5 deliveries
•   Face presentation        1 in 500 deliveries
•   Brow presentation        1 in 1000 deliveries
•   Breech presentation       1-2 in 50 deliveries
•   Shoulder presentation 1 in 200 deliveries
•   Unstable lie             1 in 350 deliveries
 Occipito – posterior position..
 In a vertex presentation when the occiput is
 placed posteriorly over the sacrum / sacro –
 iliac joint, it is called an occipito – posterior

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.
Occipito – posterior is an abnormal position of the
  vertex rather than an abnormal presentation. (In most
  of cases (90%) anterior rotation of occiput occurs.)
  But as the posterior position may give rise to
  Dystocia (abnormal labour & delivery), it is
  associated with mal presentation.
Incidence – upto 13% of all vertex presentation.

R.O.P. is 3 times more common than L.O.P.

 WHY ??
-Dextro-rotation of the uterus favours
   occipito-posterior than right occipito-
   anterior position
-The right oblique diameter is slightly longer
   than the left one
-The left oblique diameter is reduced by the
   presence of sigmoid colon
Causes :-

Not clear but factors abound –
1. CPD , Maternal kyphosis
2. Contracted pelvis:-50% or more occipito –posterior
     position is associated with either an anthropoid or
     android pelvis due to narrow fore-pelvis.
2. Fetus – deflection of fetal head favours posterior position of
     the vertex. Causes of deflection are –
a. High pelvic inclination.
b. Placenta praevia, pelvic tumors.
3. Uterus – abnormal uterine contraction.
4. Pendulous abdomen esp. in multipara.
Diagnosis: –

Inspection :-
- Abdomen looks flat below the umbilicus.

Palpation :-
Fundal height :- corresponds with period of amenorrhoea.
Fundal grip :- breech.
Lateral grip :-Foetal back is felt on rt. Flank of mother in in
   ROP & in left flank in LOP.
Fetal limbs are felt easily as knob like structure anteriorly.
Pelvic grip :-Head is not engaged.
-Cephalic prominance (sinciput) is not felt so prominent as
   found in well flexed occipito – anterior.
 -In direct occipito – posterior the small sinciput is confused
   with breech.
-Auscultation :-
FHS is best heard in flank in direct occipito – posterior / R.O.P. but
     difficult in L.O.P.

Vaginal examination :-
1.   Finding depends upon degree of flexion of head.
2.   Conformed dx. Is made during 2nd stage of labour on rupture
     of membrane by:-
    a. Sagittal suture:- occupies any of the oblique diameter of
    b. posterior fontanelle :-felt near the sacro-iliac joint.
    c. anterior fontanelle :- felt near the ilio-pectineal eminence.
Mechanism of labour –
1.    Head engages through the right oblique diameter in R.O.P. &
      Left oblique diameter in L.O.P. Because of deflection
      engagement is delayed.
2.    In most of the cases (90%) –
    a. flexion – due to good uterine contraction there is flexion of
    b. internal rotation of the head – occiput rotates to 135 degrees
      anteriorly to lie behind the symphysis pubis, shoulder rotates
      to occupy right oblique diameter.
3. Further descent & delivery of the head occurs like occipito –
   anterior position.
4. Birth of shoulders & trunk – is the same as that of occipito
   Fate of OPP
                                   Engaging diameter :- occipito-frontal
                                   11.5cm or sub-occipitofrontal 10cm.

                                                   Unfavorable (10%)
    Favorable (90%)

    3/8th rotation          Mild deflexion Moderate deflexion Severe deflexion

occipit comes under       Occiput rotate by     Non-rotation     Occiput rotate
symphysis pubis (rt/lt    1/8th circle                           posteriorly by 1/8th
occipito anterior)                            Oblique
                                              posterior            POPP/ occipito-
Normal vaginal delivery                       arrest               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.
During 1st stage:-
1. Early diagnosis
2. Fetal, maternal condition and pelvic
   assessment should be done.
3. Prevent rupture of membrane by bed
   rest in lt. lateral position.
4. Partograph to be strictly maintain.
5. Early c/s in contracted pelvis.
   Second stage                         p/v exam:- To see level of presenting part,
                          2nd stage     degree of flexion, position, caput, moulding, cx.

                                                     Unfavorable (10%)
    Favorable (90%)

Ant. 3/8th rotation          Mild deflexion Moderate deflexion Severe deflexion

occipit comes under        Occiput ant.          Non-rotation       Occiput rotate
symphysis pubis (rt/lt     rotate by 1/8th                          posteriorly by 1/8th
occipito anterior)         circle
                              Deep             posterior             POPP/ occipito-
Normal vaginal delivery
                              transverse       arrest                sacral position
   Management of DTA
                         DTA or oblique
                         posterior arrest

                        Assisted delivery

                                                     Dead baby
   Pelvis adequate               Inadequate pelvis

-Manual rotation of occiput to       C/S              Craniotomy
anterior position followed by
forceps extraction
- vacuum delivery
- forceps rotation
Manual rotation and extraction by forceps:

Under general anaesthesia the following steps are done:

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

      Spontaneous face to
      pubis delivery

                            Adequate pelvis    Inadequate pelvis    Dead baby

  Head above the ischial     Head below the spines                  Craniotomy
  spine / big baby
                                     Forceps with deep
C/S (best)      Manual rotation +    episiotomy
Prognosis –
Increased maternal morbidity due to pronlonged labour
     & increased incidence of operative delivery.

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