The document discusses the occipito-posterior position of the fetus, characterized by the occiput being positioned posteriorly over the sacrum, and outlines the incidence and causes of this position, as well as its impacts on labor. It describes the mechanism of labor, including how the head engages and potentially rotates during delivery, and outlines management strategies for both stages of labor, emphasizing the need for early diagnosis and potential interventions like cesarean sections if necessary. Additionally, it addresses complications and alternative methods of delivery in cases of labor obstruction.

1. OCCIPITO-POSTERIOR
POSITION
BY Dr. PRIYANKA C G
PG RESIDENT
OBG DEPARTMENT
KIMS KOPPAL

2. ⚫An abnormal position of the vertex rather than an
abnormal presentation.
⚫In a vertex presentation when occiput is placed
posteriorly over the sacro -illiac joint or directly over
sacrum, it is called occipito -posteriorposition.

4. sacro-illiac
position of
⚫When the occiput is placed over right
joint , Right occipito-posterior(ROP)/3RD
vertex.
⚫When the occiput is placed over left sacroilliac joint,
Left occipito -posterior(LOP).also called 4th position of
vertex.
⚫when it points towards sacrum, is called Direct
occipito-posterior .

6. INCIDENCE
⚫ ROP is 5 times more common than LOP
⚫ Presence of sigmoid colon on the left rotation of the
uterus favours ROP.
⚫At the onset of labour ,the incidence of O-P is about
10% & is much less in latesecond stageof labour.
& dextro-

8. CAUSES
⚫MATERNAL-
shapeof inlet- Anthropoid/android pelvis
more than 50% cases because the wide occiput can be
comfortably placed in wider posteriorsegmentof pelvis.

10. ⚫FETAL-Marked deflection of head favours posterior
position. Itoccursdue to
 High pelvic inclination.
 placenta previa
 pelvic tumours
 Primary brachycephaly
⚫ UTERINE –Abnormal uterinecontraction

11. Diagnosis: –
Inspection :-
- Abdomen looks flat below the umbilicus.
Palpation :-
Fundal height :- corresponds with period of
amenorrhoea.
Fundal grip :- breech.

12. Inspection- infraumbilical flattening

13. Lateral grip :-Foetal back is felton rt. Flank of
mother in ROP & in left flank, in LOP.
Fetal limbs are felteasilyas knob likestructure
anteriorly.

15. Pelvicgrip :-Head is notengaged.
-Cephalic prominance (sinciput) is not felt so
prominentas found in well flexed occipito –anterior.
-In directoccipito – posterior the small sinciput is
confused with breech.

16. -Auscultation :
FHS is best heard in flank in directoccipito –
posterior / R.O.P.
-but difficult in L.O.P.

17. Vaginal examination :-
1. Finding depends upon degree of flexion of head.
2. Confirmation madeduring 2nd stageof labour:-
a. Sagittal suture:- occupies anyof the obliquediameter
of pelvis.
b. posterior fontanelle :-felt near the sacro-iliac joint.
c. anterior fontanelle :- felt near the ilio-pectineal
eminence.

18.  Sometimes the position is not recognized until there is
delay in thesecond stageof labour.
 Thediagnosis byvaginal examination may bedifficultdue
to the formation of caput succedaneum overthe presenting
part.
 In thiscase the fingers may be passed higherto feel the free
margin of theearwhich will point to theocciput.

19. MECHANISM OF LABOUR
⚫The head engages through rightobliquediameter in
ROP & leftobliquediameter in LOP.
⚫Theengaging transversediameterof head is biparietal
(9.5cm)
⚫Anterior-posteriordiameter is either
suboccipitofrontal (1ocm) oroccipitofrontal (11.5cm).

20. IN FAVOURABLE CASES(90%)
⚫Good uterinecontraction results in good flexion of
head. normal descentoccurup to pelvic floor.
⚫Occiputrotates 3/8th of acircle(135degree) anteriorly
to lie behind symphysis pubis. shoulders rotateabout
2/8th of circle tooccupyobliquediameter.
⚫Restof the mechanism is like thatof right
occipitoanterior in ROP & left occipitotanterior in
LOP.

21. In favourable case

22. UNFAVOURABLE CASES(10%)
non rotation or malrotation
⚫Certaincases occiput fails to rotate-
 Deflexion of the head
 Weak uterinecontraction
 Flatsacrum
 Prominent ischial spine
 Convergentside walls
 Weak pelvic floor muscles
 Big baby
 Earlydrainage of liquor

23. 23

24. ⚫ 3 types results
 Incomplete forward rotation –occiput rotates 1/8th of
circle sagital suture comes to lie in bispinous diameter
results in Deep transverse arrest. It occurs in mild
deflexion of head.
 Nonrotation –both sinciput & occiput reaches pelvic
floor at same time & sagital suture lies in oblique
diameter results in Oblique posterior arrest. It occurs
inmoderate deflexion of head.

25.  Malrotation - the sinciput touches pelvic floor first
resulting in anteriorrotationof sinciput 1/8th of circle
putting occiput tosacral hollowcalled Persistent
Occiput -posterior Position of vertex. Itoccurs in
extreme deflexion. Alsocalled occipito -sacral
position.

26. ⚫In favourable circumstances in persistent
occipitoposterior position, spontaneous delivery
occurs as face to pubis. Descend of head occurs until
root of nose hinges under symphysis pubis. Delivery
of brow, vertex, occiput lastly face is born by
extension .Restitution ,external rotation &delivery of
trunkoccurs normally.

27. COURSE OF LABOUR
⚫Avg duration of both 1st& 2nd stage of labour is
increased.
⚫FIRST STAGE-
engagement isdelayed
 persistence of deflexion of head
Driving force transmitted through the fetal axis is
notalignmentwith axis of inlet.

28. Early rupture of membraneoccur.
Abnormal uterinecontraction
SECOND STAGE-delayed due to long internal
rotation or malrotation , with at times, arrest of
head
THIRD STAGE-increased incidenceof postpartum
hemorrhage & trauma togenital tract

29. M

ODE OF DELIVERY
Long anterior rotation of occiput -spontaneous or
assisted vaginal deliveryoccurs.(90%)
Short posterior rotation-spontaneous or assisted
vaginal delivery may occur as face to pubis. but there is
morechanceof perineal tear

30. ⚫Non-rotation or short anterior rotation-spontaneous
vaginal delivery highly unlikely . May progress to
prolonged orobstructed labour.

31. MANAGEMENT OF LABOUR
Earlydiagnosis
Strictvigilance with watchful expectancy hoping for
descent &anterior rotation of occiput
Judicious & timely interference if needed
Earlycaeserean section

32. Management of the first stage of labour:
The 1st stage is managed as in a normal case.
Nothing can bedone tocorrect the Malposition or to
influence the rotation of the head at this stage.
A partogram isdone to monitorthe :
1.Uterinecontraction (frequency, duration and strength
).
2.Fetal heart.
3.Dilatation of the cervix.

33. If progressive cervical dilatation does not occur
augmentation with an oxytocin drip may be tried.
If still no progress obtained in a few hours
caesarian section (C/S) is performed.
Also if there is fetal distress C/S isdone

34. Management of the 2nd stage of labour:
1.In mostcases (70% ) provided that the uterinecontractions
arestrong and thewoman isable to makegood expulsive
efforts theocciput rotates forward and normal delivery
takes place.
2.Inothercases (10% ) the baby may bedelivered face-to-
pubes with out difficulty but there is agreat risk of a
perineal tear.

35. ⚫3.In about 20% of cases there is failure of the
presenting part to rotate and descend and such
cases delivered by C/S or rotation can be enhanced
byassistance .

36. Arrest In occipito-transverse or oblique
position
Ventouse- It issuitable incaseswhere the pelvis is
adequete & non-rotation of the occiputdue to
weak contraction or lack of toneof pelvic floor .

37. Fate of OPP
OPP
Engaging diameter :- occipito-
frontal 11.5cm orsub-occipitofrontal
10cm.
Favorable (90%)
Unfavorable (10%)
3/8th rotation
occiput comes under
symphysis pubis (rt/lt
occipito anterior)
Normal vaginal delivery
Mild deflexion Severe deflexion
Moderatedeflexion
Occiput rotate by
1/8th circle
Deep
transverse
arrest
Non-rotation
Oblique
posterior
arrest
Occiput rotate
posteriorly by 1/8th
POPP/ occipito-
sacral position
Faceto pubis
delivery
Arrest

38. Alternative methods-
Manual rotation followed by forcepsextraction
Forceps rotation & extraction
Caesarean section
craniotomy

39. Half hand method

40. Full hand method

41. Manual rotation & forcep extraction
⚫First head is rotated manually till theocciput is
placed behind symphysis . It isdonewith either by
whole hand method or half hand method. Then
forceps bladesare applied.
The pelvisshould beadequate,
Baby is of averagesize
There isgood amountof liquor

42. Manual rotation and forceps delivery:
Should bedone underpudendal block orgeneral
anaesthesia.
The head is rotated with the fingers toadirect
anterior position.

43. The shoulder girdle of the fetus should be rotated
at the same time as the head by pressure through
theabdominal wall byexternal hand.
After rotation completed an obstetric forceps are
applied tocomplete thedelivery.

44. Difficulties are-
Failuretogrip head adequatelydue to lack of space.
Failuretodislodge head from impacted position
Inadequate anaesthesia
Wrong caseselection
Complications-
Accidental slippage of head
Prolapse of cord

45. Forceps rotation&extraction
It isdone byexperts
 Kielland’s forceps used.
Advantage over manual rotation
Nochance of displacementof head
Noaccidental cord prolapse
Rotationcan bedoneaboveor below the level of
obstruction

46. Caeserean section-if there is midpelviccontraction,I t
is much safer than rotation
Craniotomy- it is done in caseof dead baby

47. Occipito sacral arrest
⚫Below the
spine
Station of head
Above the
level of ischial
spine
C/S
Ventouse or
forceps with
deep
episiotomy

48. Deep transverse arrest:
Means arrest of labour when the fetal head has descended
to the level of the ischial spines and the sagittal suture lies
in the transverse diameterof the pelvis.
The occiput lies on one side of the pelvis and the sinciput
on theothersideand the head is badly flexed.

49. It is onlydiagnosed during the 2nd stage of labour.
If the head is firmly fixed in the transverse
position obstructed labour will occur

50. Management of DTA
DTAoroblique posteriorarrest
Assisted delivery
Pelvis adequate Inadequate pelvis
-Manual rotation of occiput to
anteriorposition followed by forceps
extraction
- vacuum delivery
- forceps rotation
Dead baby
Craniotomy
C/S

51. Thank you