2. Definition of Terms
• Presentation- the part of the fetus which occupies the lower
uterine segment.
• Lie – the relationship between the long axis of the fetus and the
mother (longitudinal ,Transverse and Oblique)
• Attitude- position of the fetal head in relation to the neck
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3. Definition of Terms…
Denominator- It is an arbitrary fixed bony point at the presenting part
which come in relation with the various quadrants of the maternal pelvis.
Occiput, Sacrum, Mentum, Frontal and Acromion
Position- It is the relation of the denominator to the different quadrants of
the maternal pelvis.
Cardinal movement:
Engagement,Descent,Flexion,Internalrotation,Extensition,External
rotation ( Restitution ) and Expulsion
Engagement- means maximum transverse diameter of the presenting part
passes through the pelvic brim. • For head bi-parietal diameter. • For
breech bi-trochanteric diameter 3
4. Malposition
Malposition is abnormal position of the vertex (other than
occipito-anterior position (DOA,ROA and LOA)) of the fetal
head relative to the maternal pelvis.
Malpresentation
Any fetal presentation other than a vertex presentation
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5. Etiologies of Malpresentation/Malposition
Fetal Maternal
• Multiple pregnancy
• Congenital anomalies- anencephaly,
hydrocephalus, fetal tumors, fetal hydrops
• Fetal macrosomia
• Conjoined twins
• Polyhydramnios
• Oligohydramnios
• Placenta previa
• Preterm labor/prematurity
• Uterine congenital anomalies- arcuate,
septate, didelphys, unicornuate uteri
• Contracted pelvis
• Grand multiparity
• Uterine myoma
• Genetic predispositions- family history
of malpresentations
Most known causes of mal-presentations act by preventing the natural rotation of the fetal head
to the lower segment around the 34th week or above and also by preventing the stabilization and
fixation of the fetal head in the pelvic inlet around term.
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6. Malposition
Classification of Malposition
Occiput posterior (DOP,LOP, ROP)
Persistent occiput transverse position (ROT, LOT)
Occiput posterior
Occiput posterior position is when the fetal occiput is
posterior in relation to the maternal pelvis.
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7. 1. Occiput posterior position
Most, 90%, occiput posterior positions undergo
spontaneous anterior rotation.
Transverse narrowing of the midpelvis is a risk factor.
Is associated with partial deflection of the head and hence
the occipito frontal diameter (11.5 cm) is presenting.
ROP is more common than LOP
- Large bowel on the left side
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8. Diagnosis
Suggestive abdominal findings:-
Flattened lower part of the abdomen.
Anteriorly palpable fetal limbs.
Fetal heart heard in the flank.
More marked fetal movement
On vaginal examination:-
Posterior fontanelle towards the sacrum.
Anterior fontanelle felt anteriorly if neck is flexed.
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9. • Mechanism of labor
• Two types of OP:
- Flexed OP: suboccipito bregmatic( 9.5 cm) and biparietal diameters (9.5
cm) are the presenting diameters.
- Deflexed OP: occipitofrontal( 11.5 cm) and biparietal diameters engage.
Progress depend on flexion!!
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10. Management
Labor and delivery need not differ remarkably from that with the occiput
anterior.
The possibilities for vaginal delivery:
1 -Spontaneous delivery.
2 -Forceps delivery with the occiput directly posterior.
3 -Manual rotation to the anterior position followed by spontaneous or
forceps delivery.
4 -Forceps rotation of the occiput to the anterior position and delivery
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11. • Spontaneous delivery
-Roomy outlet with relaxed perineum.
-Generous episiotomy is usually needed.
• Forceps delivery as an occiput Posterior
-Forceps put midway between the occiput and sinciput.
-Initial traction directed posteriorly and as the glabella is at the apex of pubic arch the
traction should be anterior.
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12. • Manual Rotation.
• The effective method is to rotate the sinciput
posteriorly.
• Determine the exact position.
• For ROP use the right hand to grasp the sinciput,
displacing upward to increase flexion.
• Middle finger in the frontal suture as a marker.
• The thumb and other fingers around the bitemporal
region.
• For the LOP, we use the left hand
• The free hand applied over the maternal flank to
promote rotation.
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13. Persistent occiput transverse position (ROT, LOT)
Persistent occiput transverse position is an occiput
transverse position that is maintained for an hour or more in
the second stage of labor
Classification
High transverse arrest (arrest above station +2 )
Deep transverse arrest (arrest below station +2)
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14. Causes and risk factors
Inadequate power (contraction and poor pushing)
Platypelloid and android pelvis.
Fetal head in long occipito-frontal diameter.
Diagnosis
On vaginal examination the fetal sagittal suture and
fontanelles are palpable in the transverse diameter of the
pelvis; the fetal ears can be palpated superiorly under the
symphysis and inferiorly above the sacrum/coccyx.
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15. Management
Expectant management:
If there is any progress in descent and the fetal heart rate is reassuring,
expectant management is the preferred option.
Partial or complete rotation may still occur spontaneously.
Augmentation.
Caesarean delivery if there is high transverse arrest despite adequate
uterine contraction and maternal expulsive effort
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16. Abnormal Axial Lie
Diagnosed in approximately 1 in 300 cases, at term.
Occurs if the fetal spine or long axis crosses that of the mother.
Diagnosis made by palpation or vaginal examination and
verified by ultrasound.
An arm, foot, or a shoulder be the presenting part.
Prematurity is often a factor, with abnormal lie reported to
occur in about 2 percent of pregnancies at 32 weeks, or six
times the rate found at term.
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17. Abnormal Axial Lie…
Multiparty parity, contraction or deformity of the maternal pelvis, and
abnormal placentation are also the most commonly reported clinical
factors associated with abnormal lie.
Could be – oblique or transverse or unstable.
Unstable if the fetal membranes are intact and there is great fetal
mobility resulting in frequent changes of lie or presentation.
Perinatal mortality for unstable or transverse lie varies from 5 percent
to 25 percent, with maternal mortality as high as 10 percent
• Cord prolapse occurs 20 times as it does with a cephalic presentation.
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19. Management:
• Exclude a major fetal malformation and abnormal placentation.
• Expectant management before term.
• Active intervention at or beyond 37weeks or after confirmation
of fetal lung maturity.
• External cephalic version with subsequent induction of
labor(Stabilization induction).
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20. • Cesarean delivery is indicated if:
• External version is unsuccessful or unavailable
• Spontaneous rupture of membranes occurs
• Active labor has begun with an abnormal lie
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21. Deflection Attitudes
Attitude refers to the position of the fetal head in relation to the neck.
The normal attitude is full flexion on the neck, with the fetal chin against the upper
chest.
Deflexed attitudes include various degrees of deflection or even extension of the fetal
head on the neck.
Management
• Spontaneous conversion to a more normal flexed attitude or further extension of an
intermediate deflection to a fully extended position commonly occurs as labor
progresses.
• Cesarean delivery is the only appropriate alternative when arrest of progress is
observed.
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22. Malpresentation
• Any fetal presentation other than a vertex presentation
• Normal presentation is vertex presentation with flexed attitude.
• The fetus normally assumes a vertical orientation or lie and a cephalic
presentation, with the fetal vertex flexed on the neck(95%).
• Deviation occurs from the normal lie, presentation, or flexion
attitude , fetal malpresentation.(5%)
• Are associated with maternal and perinatal morbidity and
mortality much higher than the vertex presentation.
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23. Presentation may be
Cephalic 95%
Vertex 99%
Face 1:500
Brow 1:1500
Breech 3 - 4% at term
Shoulder 1:200
Compound
Cord presentation
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25. Face presentation
• Is characterized by a longitudinal lie and full extension of the
fetal head on the neck, with the occiput against the upper back.
• The fetal chin (mentum) is chosen as the point of designation
during vaginal examination.
• Incidence is 1 in 500 deliveries.
• Many infants with a face presentation have malformations.
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26. Etiologies
• Conditions that favor extension or prevent head flexion
– Fetal neck soft tissue masses or goiter
– Preterm fetuses
– coils of cord around the neck
– Hydramnios
– Anencephaly found in one third of the cases
– Contracted pelvic (specially inlet)
– High parity
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27. In face presentation:
• The presenting diameter in Mentoanterior is Sub-mento-bregmatic(9.5cm)
• The presenting diameter in Mentoposterior is bregmotrachelar( 18cm)
Denominator in face presentation – Mentum
• The prognosis for labor with a face presentation depends on the orientation
of the fetal chin.
• At diagnosis: - Mentoanterior 60 to 80%
- Mentoposterior 20 to 25 %
- Mentotransverse 10 to 15 %
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28. Attempts to convert a face presentation manually into a vertex presentation, manual or
forceps rotation of a persistently posterior chin to a mentum anterior position, and internal
podalic version and extraction are dangerous and not attempted. In the case of an average
or small fetus, adequate pelvis, and hypotonic labor, oxytocin may be considered.
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29. • Most mentotransverse and 25 to 33 percent of
mentoposterior infants will rotate .
• In mentoanterior vaginal delivery is possible as the vertex fit
into the hollow of the sacrum and the chin fits under the
symphysis.
• The birth of the head in mentoposterior position is
impossible as the fetal brow pressing over the symphysis
precludes flexion.
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32. Diagnosis
Suggestive abdominal finding:
Deep depression between the back and the head…’S’ shape of the fetal spine
Groove may be felt between the occiput and the back
On vaginal examination
Fetal chin, mouth and nose palpated.
The mouth with the two malar bone prominences make a triangle (unlike in breech
where the anal orifice with two trochanteric eminences are in a line)
Radiography
•Demonstration of the hyperextended head with the facial bones at or below
the pelvic inlet
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33. To differentiate face from breech
1. Face – sucking reflex, palpate gum, mentum + two maxillae
makes a triangle
2. Breech – meconium may be obtained, anus is on midline b/n the
ischial tubrosities, anal sphincter tone is more than the tone of the
mouth.
3. X-ray
Hyper extended head
Facial bones at or below pelvic inlet
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35. Management of Face Presentation
• Overall, 70% to 80% of infants with face presentation can be
delivered vaginally, either spontaneously or by low forceps,
whereas 12% to 30% require cesarean delivery.
• Assess fetal size, pelvic adequacy and the presence of
anomalies at initial diagnosis.
• In the absence of a contracted pelvis and with effective labor,
successful vaginal delivery usually will follow
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36. • Fetal heart rate monitoring is probably better done with
external devices to avoid damage to the face and eyes
• Follow labor progress and ascertain internal rotation to mento
anterior position
• Manual rotation to mento anterior position, internal podalic
version and extraction are an outdated management
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37. Persistent mento-posterior presentation:
• Mento-posterior in the later part of the first stage(after 6 cm of
cervical dilatation) and second stages of labor.
• If fetus is alive → Cesarean delivery
• If the fetus is dead → Craniotomy if all the prerequisites are
met
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38. Complications
• Prolonged labor: oxytocin may be considered in
hypotonic labor?
• Worsening of the fetal condition is 10 fold higher.
- Continuous intrapartum electronic fetal heart rate
monitoring.
- Care must be taken in the placement of an electrode
to avoid cosmetic injury to the face.
• Nerve damage to the neonate with forced flexion during
C/S.
• Laryngeal and tracheal edema resulting from pressures of
the birth process.
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39. Brow presentation
• Occupies a longitudinal axis, with a partially deflexed cephalic attitude,
midway between full flexion and full extension.
• The portion of the head between the orbital ridge and the anterior fontanel
presents at the pelvic inlet.
• The frontal bones are the point of designation.
• The engaging diameters are the mentovertical (13.5cm) and biparietal
(9.5cm).
-the largest pelvic diameter is 13 cm.
-labor is impossible with normal baby and fetus. 39
40. • Frontum anterior is reportedly the most common position at diagnosis,
occurring about twice as often as either transverse or posterior positions.
• Incidence is 1 in 10,000 ( Williams), 1 in 1,500( Gabbe).
• On abdominal palpation both the occiput and chin can be palpated easily.
• Brow presentation is commonly unstable and often converts to a face or vertex
presentation , about 91% in adequate pelvimetry.
• Risk factors: -Cephalopelvic disproportion
-Prematurity
-Great parity
-An open fetal mouth pressed against the vaginal wall.
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41. One unexpected cause of persistent
brow presentation may be an open
fetal mouth pressed against the
vaginal wall, splinting the head and
preventing either flexion or extension
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42. Diagnosis
Suggestive abdominal finding:
Occiput felt above Sinciput.
Free head with ROM
Unengaged head in primigravida at term
Prolonged labor
Leopold’s palpation- “ military” attitude
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43. Perivaginal
Diagnosis is rare before labor
Frontal suture
Large anterior fontanel 4 lines felt unlike 3 of posterior
fontanel
Orbital ridges, eyes, roots of nose
In brow presentation extensive moulding & caput occurs
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44. Management
Antenatal
Expectant since 50% undergo spontaneous conversion to face(20%) or vertex(30%).
The patient should come to hospital immediately if labor starts or membrane ruptures.
In labor
If labor progresses with no distress no interference, chance of change to face or
vertex in 2-3 hours.
• If brow presentation diagnosed in early labor with no maternal OR fetal
compromise, we may wait and review the condition after 2 to 3 hours.
• If still brow … emergency cesarean section!
• If brow presentation diagnosed in established labor with signs of obstructed labor
emergency cesarean section!
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45. Management…
• Mechanism of labor – varies with size of the fetus.
• Very small fetus & large pelvis – engagement and delivery is possible.
• Large fetus – engagement is impossible unless:
extensive moulding,
flexion to vertex,
extension to face.
• Forced conversion of the brow to a more favorable position with forceps or manual is
contraindicated.
• Trial of labor with careful monitoring of maternal and fetal condition may be
appropriate.
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46. Management…
Persistent brow presentation is brow presentation in the
later part of the first stage (after 6 cm of cervical dilatation)
and second stages of labor.
If the fetus is alive deliver by cesarean section.
If the fetus is dead: Perform craniotomy if the cervix is
fully dilated and the head is accessible and other
prerequisite for craniotomy are met:
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47. Management…
Deliver by caesarean section if:-
The cervix is not fully dilated or station is high.
The operator is not proficient in craniotomy.
Do not use an obstetric vacuum or forceps with brow presentation.
Augmentation of labor is also not generally recommended in brow
presentation.
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48. Complications
Rupture of fetal membranes
Cord prolapse → fetal distress →fetal death
Marked molding
Rupture of fetal membranes
Prolonged and complicated labour
Maternal distress, dehydration, ketoacidosisInfection
No engagement of presenting part
Obstructed labour → uterine rupture →maternal death
Maternal complication
Fetal complication
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49. Shoulder presentation
• Shoulder presentation occurs with the fetus is in the
.
• In late labor, shoulder presentation may be accompanied by
a hand prolapse.
• Diameter attempting to be delivered in shoulder
presentations is the crown-rump length
• The long axis of the fetus is approximately perpendicular to
that of the mother.
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50. Shoulder presentation…
• The shoulder is usually over the pelvic inlet, shoulder presentation.
• The head lies in one iliac fossa, and the breech in the other.
• The acromion and the back are important for designation.
• The dorsum can be directed anteriorly or posteriorly, superiorly or
inferiorly.
• Incidence is 1 in 335 singleton fetuses.
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52. Risk factors
High parity Relaxed and pendulous abdomen The
uterus falls forward, and deflecting the long axis of the fetus away
from the axis of the birth canal
Preterm fetus
Placenta previa
Abnormal uterine anatomy
Hydramnios
Contracted pelvis
Multiple pregnancy.
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53. Diagnosis
Abdominal Examination finding
• The abdomen is unusually wide.
• Fundal height is less than gestation age.
• The uterine fundus extends to only slightly above the umbilicus.
• No fetal pole is detected in the fundus.
• Ballot table head is found in one iliac fossa and the breech in the other.
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54. Vaginal examination
• In delayed and neglected cases the hand and arm may prolapse.
• Cord prolapse rate is the highest among the malpresentations (20%).
• Depending on the position of dorsum, the shoulder, hands or parts of
the ribs may be felt on vaginal exam.
• Clinical pelvimetry should be performed
Sonography
• In addition to confirming the diagnosis, presence of congenital
anomalies, placenta previa, uterine anomalies and fetal size
assessment should be made.
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56. Management
• Vaginal delivery of a fully developed newborn is impossible with
a persistent transverse lie.
• After rupture of the membranes the fetal shoulder is forced into
the pelvis, and the corresponding arm frequently prolapses.
• The onset of active labor in a woman with a transverse lie is an
indication for emergency cesarean delivery.
• ECV should be tried if the membrane is intact and no
contraindications.
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57. Management…
• If the pelvis is large and the fetus is small, spontaneous evolution could
take place:
oArm and shoulder descend behind the symphysis.
oThe chest descend into the pelvis.
oThe breech follows.
oDelivery follows as with breech with one arm extended.
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60. If the fetus is small, less than 800 g, and dead it may double upon itself
and get expelled, conduplicato corpore.
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61. Compound Presentation
• Compound presentation is when a fetal extremity prolapses alongside the main
presenting part.
• It usually is the hand alongside the fetal head.
• Incidence of 1 in 700 deliveries.
• Although maternal age, race, parity, and pelvic size have been associated with
compound presentation, prematurity is the most consistent clinical finding.
Diagnosis
Antepartum obstetrical ultrasound examination.
vaginal examination: Irregular mobile fetal part adjacent to the larger presenting part
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62. Intrapartum management
• Observation in normally progressing labor because 75% of
vertex/upper extremity combinations deliver spontaneously.
• Closely monitor labor. The prolapsed extremity should not be
manipulated as it may retract with the descent of the main presenting
part.
• Spontaneous vaginal birth can occur only when the fetus is very small
or dead and macerated.
• Cesarean delivery is indicated if there is protraction or arrest of labor.
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63. • Augmentation of labor and instrument use is not recommended
• Occult or undetected cord prolapse is possible, and, therefore,
continuous electronic FHR monitoring is recommended.
• Cord prolapse occurs in 10% to 20% of cases.
Outcomes:
- Most cases result in uncomplicated vaginal delivery( up to 75%).
- Ischemic necrosis of the arm (both neurologic and musculoskeletal
injury).
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64. Parietal presentation/Asynclitism/Lateral flexion
Synclitism: The posture in which the 2 parietal bones are at the
same level.
Asynclitism: The posture in which one parietal bone is at a
lower level than the other due to lateral inclination of the head.
Asynclitism is beneficial in bringing the shorter subparietal or
supraparietal diameter (9 cm) to enter the pelvis instead of the
longer biparietal (9.5 cm).
Slight degree of asynclitism may occur in normal labour
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