2. •Vertex presentation
•Occiput in post. Segment of pelvis overlying the
sacroiliac jt and sacrum
• 3 positions described:
1. Right occipitoposterior
2. Left occipitopoterior
3. Direct occipitoposterior

3. AETIOLOGY
SHAPE OF PELVIC INLET- anthropoid or
android pelvis
FETAL FACTORS- marked deflexion-
1) high pelvic inclination
2) placenta on ant. Wall of uterus
3) back on the right side
UTERINE FACTORS- abnormal uterine
contractions

4. DIAGNOSIS
ABDOMINAL EXAMINATION
Subumbilical flattening
Back is in one or the other flank so clinically
not felt
Limbs felt anteriorly
Shoulder in flanks
Unengaged or high head at term
Occiput and sinciput at same level
Fetal heart sounds in the flanks and are
frequently indistinct

5. VAGINAL EXAMINATION
Early In Labour-
 Early rupture of membranes
 Sagittal suture in right oblique diameter
 Post. Fontanelle in right posterior quadrant
and ant. Fontanellae in left anterior quadrant
 Both fontanelle easily palpated

6. Late In Labour
 Large caput present obscuring the sutures
 Pinna points occiput
 Perineum gapes much before head distends it
and premature straining can occur
 Difficulty in applying forceps in unrecognized
occipitoposterior

7. MECHANISM OF LABOUR
ENGANGING DIAMETER
Suboccipitofrontal-10.5cm
Occipitofrontal-11.5cm

8. COURSE OF LABOUR
Anterior rotation- 90% cases, occiput
rotates anteriorly through 3/8 of circle
and baby born occipitoanterior.
Engagement may be delayed and labour
may be longer because of deflexion.

9. Posterior Rotation And Face To Pubis
Delivery
Head is deflexed.
Engaging diameter is occipitofrontal.
Sinciput rotates anteriorly then occiput rotates
posterioirly
Extreme flexion followed by extreme
extension
Perineal tears common
Liberal episiotomy needed
Occipitosacral position and face to pelvis are
more common anthropoid pelvis

10. Failure Of Rotation
Persistent occipitoposterior is the absence of
rotation and head remains as ROP or LOP
Deep transverse arrest is defined as head
being arrested with sagittal suture in
transverse diameter at the level of ischial
spine, after full dilation of cervix and inspite of
good uterine contractions

11. Reasons-
Deflexion of the head
Inefficient uterine contraction
Weak pelvic floor preventing anterior rotation
Pendulous abdomen and poor muscle tone
Cephalopelvic disproportion and android
pelvis

12. MANAGEMENT
Most of the malpositions will rotate
anteriorly and the baby will be born
spontaneously as occiput anterior
Posterior rotation- labour longer
- Judicious use of fluids, liberal
episiotomy and analgesia needed
-partogram essential
- -oxytocin augmentation

13. DEEP TRANSVERSE ARREST
1. Caesarean section-android pelvis,
cephalopelvic disproportions, traumatic
vaginal delivery causing intracranial
haemorrhage
2. Vacuum extraction- ideal- cup at posterior
fontanelle- promotes flexion, thus decreases
presenting diameter- promotes autorotation
suited for the pelvis- less traumatic, no need
for analgesia

14. 3. Manual rotation- under GA
-right hand grasps the sinciput, displacing it and
there by increasing flexion
- Small bitemporal diameter allows more space
for the thumb and finger to have firm grasp
across the temple with middle finger on the
frontal suture
- In LOP, left hand used- sinciput rotated and
forceps or vacuum used

15. 4. Forceps Rotation-
- Keilland forceps used
- Under GA
- In anteroposterior direction and rotation
carried out
- Adv- forceps need not be reapplied

16. PERSISTENT
OCCIPITOPOSTERIOR
Oxytocin augmentation tried
Most cases delivery as occipitoposterior
with face to pelvis, assisted with forceps
or vacuum
Rotation to occipitoanterior can be
attempted
Caesarean section otherwise

17. If any of the attempt to deliver the baby
vaginally fails.. Immediate CS should be
done
Otherwise, fetus may die and craniotomy by
experienced hands or CS must be done

18. FACE PRESENTATION
Cephalic presentation where the attitude is
one of complete extension, presenting part is
face and denominator is the chin or mentum
Engaging diameter is submentobregmatic-
9.4cm
Primary face presentation are present before
onset of labour and are rare
Secondary caused by extension during labour
and is most common

19. POSITIONS
Left mentoanterior(LMA)
Right mentoanterior(RMA)
Right mentoposterior(RMP)
Left mentoposterior(LMP)
70% are mentoanterior and 30% posterior.

20. INCIDENCE AND
AETIOLOGY
Incidence- 1 in 500
Maternal Causes
- contracted pelvis
- obliquity of uterus
- multiparity or pendulous abdomen

21. Fetal Factors
-anencephaly and iniencephaly
-cord around the neck
-tumours of neck like congenital goitre
-spasm of sternocleidomatoid muscle
-dolicocephalic head

22. DIAGNOSIS
ABDOMINAL EXAMINATION
In mentoanterior, back is felt with difficulty as it
is posterior and limbs anteriorly
Head remains high
Cephalic prominence is the occiput and on the
same side as the back
Groove b/w the head and back is prominent
Fetal heart sounds are transmitted through the
chest and heard well anteriorly in
mentoanterior

23. VAGINAL EXAMINATION
-conical bag of membranes
- chin, mouth, nose, malar eminences and
supraorbital ridges are felt
-in mentoanterior, chin is in one ant. Quadrant
and forehead in opp post. Quadrant
-done gently and without cream to avoid injury
to eyes

24. MECHANISM OF LABOUR
MENTOANTERIOR POSITION
1. Engagement
-engaging diameter- submentobregmatic-9.4cm
-biparietal diameter-7cm
This diameter pass only when face low down in
perineum
-when face distending the vulva, head engaged

25. 2. DESCENT WITH INCREASING
EXTENSION
-Resistance encountered by extension
-occiput pushed towards back of fetus, while
chin descends
3. INTERNAL ROTATION
-Rotates anteriorly through 45°towards
symphysis
Neck traverse the posterior surface of
symphysis pubis

26. 4. FLEXION
-head born by flexion
-chin pivots under symphysis pubis and the
mouth, nose, orbit, forehead ,vertex and
occiput are born by flexion
5. RESTITUTION AND EXTERNAL ROTATION
-of chin occurs towards the side to which it was
originally directed and the shoulder are born
as in vertex

27. MENTOPOSTERIOR
-2/3RD cases rotate anteriorly through 3/8th circle
and deliver as mentoanterior
-some in oblique diameter and some rotate
posteriorly into the hollow of sacrum
-neck too short to span in the 12cm of the ant.
Aspect of sacrum
-shoulders get impacted along with head making
delivery impossible
-engaging diameter is sternobregmatic-17cm
-no mechanism of labour

28. CAUSES OF PROLONGED LABOUR
Face is less effective dilator of cervix
No moulding of face
More chance of rupture of membranes
Long internal rotation in mentoposterior
Internal rotation occurs only late in 2nd stage

29. COMPLICATIONS
MATERNAL
Prolonged labour
Increased risk of operative delivery
Obstructed labour in persistent
mentoposterior

30. FETAL
Face after delivery is oedematous
Laryngeal oedema can also occur- baby
watched for 24 hrs
Congenital malformations like anencephaly
Birth asphyxia due to cord prolapse and
prolonged labour

31. MANAGEMENT
Mentoanterior, forward rotation in
mentoposterior- labour allowed
CPD, anencephaly, other anomalies,
persistent mentoposterior, obstructed
labour- CS DONE
Dead baby- CS or craniotomy

32. BROW PRESENTATION
Most unfavourable
Attitude is one of partial extension,
presenting part being the area between the
ant. Fontanelle above and glabella and
orbital ridges below and denominator is
forehead or frontum
Presenting diameter is verticomental-
13.5cm
Transitory presentation- flex or extend

33. INCIDENCE AND
AETIOLOGY
INCIDENCE-1 in 1000
CAUSE- similar to face presentation and
include any factors that interfers with
flexion of head

34. DIAGNOSIS
Rarely made before labour
ABDOMINAL EXAMINATION
High mobile head, which feels large from
side to side
Cephalic prominence is the occiput and is on
same side as back and groove between
cephalic prominence and back is less
prominent than in face presentation

35. VAGINAL EXAMINATION
Membranes felt in early labour
Anterior frontanelle is felt at one end and root
of nose and orbital ridges at other end of
oblique or transverse diameter
Nose and mouth are palpable but not the chin

36. MECHANISM OF LABOUR
Presenting diameter - verticomental
No mech of labour for persistent brow
presentation
Spontaneous labour only if baby very
small or pelvis large
In persistent brow, verticomental dia is
shortened & the occipitofrontal dia
elongated with marked moulding and
large caput on forehead

37. COMPLICATIONS
Both maternal and fetal risks are more
MATERNAL
Obstructed labour and rupture uterus
FETAL
Birth asphyxia

38. MANAGEMENT
ANTEPARTUM
Wait till labour
EARLY LABOUR
If membrane not ruptured wait for correction
After membrane rupture, brow presentation
diagnosed and in persistent brow presentation
–CS done
Prologed labour with head high.. Brow
presentation must be suspected

39. LATE LABOUR
If features of obstructed labour or if fetus
dead- immediate CS done
If baby dead- also craniotomy

40. SHOULDER PRESENTATION
AND TRANSVERE LIE
Long axes of fetal and maternal ovoid
are approximately at right angles to
each other and shoulder is presenting in
the pelvic inlet.
Denominator- acromion
POSITIONS
Right acromial
Left acromial

41. DEPENDING UPON DIRECTION OF THE
BACK
Dorsoanterior
Dorsoposterior
Dorsosuperior
Dorsoinferior

42. INCIDENCE AND
AETIOLOGY
Incidence- 1 in 500
MATERNAL FACTOR
Multiparity
Contracted pelvis
Uterine anomalies like septate,bicornuate
and arcuate uterus
Placenta praevia
Fibroid in the lower segment

43. FETAL FACTORS
Prematurity
Multiple pregnancy
Polyhydraminos
IUD

44. DIAGNOSIS
ABDOMINAL EXAMINATION
Transversely stretched
Fundal height less than period of gestation
No Fetal pole at fundus
Ballotable head in one flank & breech in the
other
In dorsoanterior, back is felt a uniform
reistance acros the front of abdomen
In dorsoposterior, limbs are felt anteriorly
Empty pelvic grip

45. VAGINAL EXAMINATION
Conical bag of membranes with a high
presenting part
Hand/shoulder/elbow may be felt as a
uniform resistance across the front of
abdomen
Shoulder can be identified by ribs running
parallel to each other
Late in labour, shoulder may be wedged in
the pelvis and hand freequently prolapse into
the vagina

46. Thumb of the prolapsed hand, when
supinated points to head
To side, to which the prolapsed hand
belongs, can be determined by shaking hand
with the fetus. If the right hand is required,
prolapsed hand is the right and viceversa
ULTRASONOGRAPHY
Confirms diagnosis and position
Rules out anomalies
Rules out placenta praevia

47. MECHANISM OF LABOUR
NO mechanism of labour
Spontaneous version to breech or by
spontaneous rectification to vertex can occur
Rarely if fetus small or dead delivery occurs
by:
- Spontaneous expulsion or birth corpora
conduplicata where fetus is expelled doubled
up
- Spontaneous evolution where breech and
trunk are expelled followed by head

48. NEGLECTED SHOULDER PRESENTATION
Due to ill fitting presenting part, membranes
may rupture early and freequently ensues cord
prolapse, once labour commence
A labour pain becomes stronger, the shoulder
forced into the pelvic inlet
Nullipara- uterine inertia
Multipara-bandl ring or pathological retraction
ring-obstructed labour- neglected shoulder
presentation
Mother-exhausted,febrile and urine show ketone
bodies-uterine rupture- death of both mother
and baby

49. COMPLICATIONS
MATERNAL
Increased chance of caesarean section
Obstructed labour or ruptured uterus
FETAL
Birth asphyxia due to cord prolapse and
in obstructed labour

50. MANAGEMENT
EXTERNAL CEPHALIC VERION
At term or early in labour if membranes
intact and not contraindicated
More successful in multipara
If successful followed by stabilizing
induction
More success than for breech

51. CAESAREAN SECTION
Best option
When ECV fails and CI
Transverse inscision
NEGLECTED SHOULDER PRESENTATION
If baby dead-CS or craniotomy

52. Reference
Shiela B, Text book of Obstetrics.