1. MALPRESENTATIONS AND MALPOSITIONS
Definition of key terms
Fetal presentation
The first part of the fetus that enters the pelvic inlet

2. Malpresentation
It is the situation where the fetus within the uterus is in any position that is not cephalic "head down"

3. Fetal Position
Relationship of the presenting part to the four quadrants of the maternal pelvis
Malposition
Any cephalic position other than occiput anterior
Fetal Attitude
Relationship of the fetal body parts to each other. Normally, it is general flexion

6. Diameters of the fetal skull

8. Dangers of Malpresentations
Ill fitting presenting part
-The fore waters are not protected from the forces of uterine contractions thus are forced through an incompletely dilated cervix
Early rupture of membranes which may result in cord prolapse
Irregular and poorly sustained contractions
In parous women labor may progress well despite an ill-fitting presenting part

9. Malpresentations such as brow or shoulder may predispose to obstructed labor and uterine rupture if not recognized early

10. Diagnosis of Malpresentations
Abdominal Examination
Abnormal lie
In longitudinal lie the presentation is either head or breech
Unusual width of the head in both face and brow presentation

11. Vaginal Examination
The mouth and anus of the fetus may be mistaken
For the mouth-the tongue may be felt
The gums – are firm
Soft lips
For the anus – there is grip on examining finger
Presence of nodules of sacral spine
If in doubt avoid use of force as other tissues may be damaged

12. The foot and the hand may be mistaken
Differences – for the foot the heel is apparent if fingers are run fro ankle to toe
-The toes are roughly equal in length
For the hand – absence of the heel if fingers are run from the wrist to the palm
-The fingers are equal with the thumb separate from other fingers

13. The shoulder is identified by the humerus, scapula, acromion process, clavicle and ribs
The knee and elbow may be mistaken
Differences – the knee has a hollow while the elbow has the point of the olecranon process

14. Occipitoposterior Positions (OPP)
Definition
It is a vertex presentation where the occiput is placed posteriorly over the sacro-iliac joint or directly over the sacrum.
Right occipitoposterior (ROP) is more common than the left occipitoposterior (LOP)
This is because the left oblique diameter is reduced by the presence of sigmoid colon
The right oblique diameter is slightly longer than the left one

15. OPP Cont,.
The most common malposition of the occiput occurring approximately in 10% of labors.
Persistent occipitoposterior position results from a failure of the internal rotation prior to delivery
The vertex is presenting but the occiput lies in the posterior rather than the anterior part of the pelvis, as a result the fetal head is deflexed and larger diameters of the skull present.

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18. AETIOLOGY Maternal causes Bicornuate uterus Fibroids Pelvic tumor
Non gynaecoid pelvis
Post traumatic
Contracted pelvis
Polyhydramnios
Oligohydramnios
Fetal causes
Prematurity
Multiple gestation
Large fetus
Large fetal head
Congenital abnormalities
Nuchal cord

19. Diagnosis Antenatal diagnosis
Inspection there is a saucer shaped depression at or below the umbilicus. The depression is caused by the ‘dip’ between the head and the lower limbs of the fetus
The outline created by the high unengaged head can look like a full bladder

20. Palpation
The back is difficult to palpate as it is to the maternal side at times almost adjacent to the maternal spine
The limbs can be felt on both sides of the midline
The breech is easily palpated at the fundus

21. The head is usually high – a posterior position being the most common cause of non-engagement in a primigravida at term
Auscultation
The fetal back is not well flexed so the chest is thrust forward and therefore the fetal heart can be heard in the midline

22. Diagnosis during labor
Complains of continuous and severe backache worsening during contractions
The large and irregularly shaped presenting circumference does not fit well on the cervix
The makes membranes to rupture spontaneously at an early stage of labor and the contraction may be inco-ordinate
Descent of the fetal head can be slow even with good contractions
Early desire to push as the occiput is pressing on the sacrum

23. Vaginal examination
Location of the anterior fontanelle in the anterior part of the pelvis is diagnostic but it may be difficult if caput succedaneum is present

24. Care during labor
Anticipate long and painful labor because the deflexed head does not fit well on the cervix and therefore does not produce optimal stimulation for uterine contractions.

25. First stage of labor
Continuous support by the midwife will help mother and partner cope with labor
Provide massage and other comfort measures
Encourage change in posture and position
The all-fours position may relieve some discomfort- evidence suggest that this position may aid rotation of the head

26. Due to prolonged labor, the mother may be dehydrated
Due to prolonged labor, the mother may be dehydrated. Prevent dehydration
Discourage early pushing as the woman has a strong desire to push which may make the cervix edematous
Encourage change of position and breathing techniques if the woman has a desire to push early

27. Avoid premature rupture of membranes by:-
Bed rest
Avoiding straining and
Minimize vaginal examinations

28. Second stage of labor
Confirm full dilatation of the cervix by VE because moulding and formation of caput succedaneum may bring the cervix into view while the anterior lip remains
Encourage an upright position if the head is not visible at the onset of second stage
Continue monitoring both maternal and fetal condition closely

29. Mechanism of the right occipitoposterior position(long rotation)
The lie is longitudinal
The attitude of the head is deflexed
The presentation is vertex
The position is right occipitoposterior
The denominator is the occiput
The presenting part is the middle or anterior area of the left parietal bone
The occipitofrontal diameter, 11.5 cm lies in the right oblique diameter of the pelvic brim

30. Mechanisms cont,.d
Flexion: Descent takes place with increasing flexion. The occiput becomes the leading part.
Internal rotation of the head: The occiput reaches the pelvic floor first and rotates forwards 3/8 of the circle along the right side of the pelvis to lie under the symphysis pubis. The shoulders follow, turning 2/8 of a circle from the left to the right oblique diameter.

32. Crowning: The occiput escapes under the symphysis pubis and the head is crowned.
Extension: The sinciput, face and chin sweep the perineum and the head is born by a movement of extension.
Restitution: The occiput turns 1/8 of a circle to the right and the head realigns itself with the shoulders.

33. Internal rotation of the shoulders: The shoulders enter the pelvis in the right oblique diameter; the anterior shoulder reaches the pelvic floor first and rotates forwards 1/8 of a circle to lie under the symphysis pubis.
External rotation of the head: At the same time the occiput turns a further 1/8 of a circle to the right.
Lateral flexion: The anterior shoulder escapes under the symphysis pubis, the posterior shoulder sweeps the perineum and the body is born by a movement of lateral flexion.

34. Normal mechanisms Occurs in 90% of cases
Deflexion is corrected and complete flexion occurs
The occiput meets the pelvic floor first
Long internal (anterior) rotation of 3/8 occurs bringing the occiput anteriorly and the fetus is delivered normally

36. Factors favoring long anterior rotation
Well flexed head.     
Good uterine contractions.              
Roomy pelvis.
Good pelvic floor.     
No premature rupture of membranes.

37. Causes of failure of long anterior rotation
Deflexed head.                          
Uterine inertia.
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.            
Lax or rigid pelvic floor.
Premature rupture of membranes or its rupture early in labour.

38. Abnormal Mechanisms Occur in 10% of cases Deep transverse arrest
The head descends with some increase in flexion. The occiput reaches the pelvic floor and begins to rotate forwards. Flexion is not maintained and the occipitofrontal diameter becomes caught at the narrow bispinous diameter of the outlet.
Arrest may be due to weak contractions, a straight sacrum or a narrowed outlet.

39. Short internal rotation -Persistent occipitoposterior
The term ‘persistent occipitoposterior position’ indicates that the occiput fails to rotate forwards. Instead the sinciput reaches the pelvic floor first and rotates forwards
The occiput goes into the hollow of sacrum
The baby is born facing the pubic bone (face to pubis)

40. Complications Obstructed labor
Maternal trauma – delivery of the baby in persistent OPP if previously undiagnosed may cause a third degree tear
Neonatal trauma
Cord prolapse
Cerebral hemorrhage

41. FACE PRESENTATION
Occurs when the attitude of the head is one of complete extension, the occiput of the fetus is in contact with its spine
Incidence is 1 in 500 or less

42. Causes Anterior obliquity of the uterus
The uterus of a multiparous woman with slack abdominal muscles and a pendulous abdomen will lean forward and alter the direction of the uterine axis
This causes the fetal buttocks to lean forwards with the force of contractions directed towards the chin rather than the occiput resulting in extension of the head

43. Contracted pelvis
In the flat pelvis the head enters in the transverse diameter of the brim and parietal eminences may be held up in the obstetrical conjugate, the head becomes extended and face presentation develops

44. Polyhydramnios
If the vertex is presenting and the membranes rupture spontaneously, the resulting rush of fluid may cause the head to extend as it sinks into the lower uterine segment

45. Congenital abnormality
Anencephaly can be a cause of face presentation.
Absence of the vertex in cephalic presentation can cause a forward thrust of the face resulting in a face presentation

46. Position Left mento-anterior- commonest Right mento-anterior
Left mento-posterior
Right mento-posterior

47. Right mento-posterior
Longitudinal lie. Face presentation. Left and right anterior and right posterior positions.
Left mento-anterior
Right mento-anterior
Right mento-posterior

48. Mechanisms of presentation
Characterized by extreme extension of the fetal head so the face (rather than the skull) presents to the birth canal

49. Diagnosis Abdominal examination
Inspection:-there is no visible bulging of the flank, due to “S” shaped fetal spine.
Palpation :- the diagnostic features in mento- anterior and mento-posterior are as follows:-

50. Mento anterior Mento posterior Lateral grip Pelvic grip auscultation
Fetal limbs are felt anteriorly.
Back is on the flank & is difficult to palpate.
The chest is thrown anteriorly against the uterine wall & is often mistaken for back.
Head seems big & not engaged.
Sinciput is to the side towards the back lies.
Groove between the head and back is not so prominent.
1. FHS is distinctly audible anteriorly through the chest wall of the fetus.
Mento posterior
1. Back is felt to the front and better palpated only towards the podalic pole because of extension of spine.
Same
The groove is prominent.
1. FHS is not so distinct and is audible on the flank.

51. Generally diagnosed on vaginal examination in labor
Presenting part is high soft and irregular
The diagnostic features are palpating the mouth with hard alveolar margins, nose, hard gums, supraorbital ridges and mentum. The fetus may suck the examining finger
As labor progresses the face becomes edematous making it more difficult to distinguish from breech
NB The anus has sphincter tone & meconium stained while the mouth has sucking reflex.

52. Mechanisms of a left mento-anterior position
The lie is longitudinal
The attitude is one of extension of head and back
The presentation is face
The position is left mento-anterior
The denominator is the mentum
The presenting part is the left malar bone

53. Possible course and outcomes of labor
Prolonged labor
Mento-anterior positions
Mento-posterior positions
Persistent mento-posterior position

54. Management of labor First stage :-
Face presentation is conformed by abdominal and vaginal examination.
Routine observations of maternal and fetal condition as in a normal labor
Assess fetal size, malformations and pelvis
Partograph should be maintained
Bed rest
Maintain proper nutrition

55. Second stage:- Face presentation Dead fetus Mento-anterior.
Face presentation
Dead fetus
Mento-anterior
Mento-posterior
LSCS
90% case normal spontaneous vaginal (face to pubis) delivery with liberal episiotomy
Craniotomy

56. Complications Maternal :- Prolonged labour Obstructed labor
High operative interference
Maternal trauma
Fetus:-
Cerebral hemorrhage
Hypoxia
Facial bruising
Operative delivery
Cord prolapse
Laryngeal edema

57. BROW PRESENTATION
In brow presentation the fetal head is partially extended with the frontal bone, which is bounded by the anterior fontanelle and the orbital ridges, lying at the pelvic brim
The presenting diameter is mento-vertical (13.5 cm)
Incidence: 1:1400

58. Mechanisms of presentation
The head is extended such that attitude is halfway between flexion (vertex) and hyperextension (face)
Usually transitional- when the head is in the process of converting from a vertex to a face or vice versa
The presenting part is between the facial orbits and anterior fontanelle
The presenting diameter is mentoverticle (MV) of 13.5cm

60. Diagnosis
Brow presentation is not usually detected before the onset of labor
Abdominal palpation
The head is high and appears unduly large and does not descent in the pelvis despite good uterine contractions
Other findings are same as face presentation except sinciput and the groove between it and back are less prominent

61. Diagnosis cont,.d Vaginal examination
The presenting part may be high and difficult to reach
Anterior fontanelle felt on one side of the pelvis as well as the orbital ridges
A large caput succedaneum may mask these landmarks in prolonged labor

62. Management in labor Initially expectant
50-75% will either flex to a vertex, or extend to a face with contractions from behind meeting soft tissue and bony resistance below and will therefore deliver vaginally
High incidence of prolonged labour and dysfunctional labour
Persistent brow
The diameter is undeliverable vaginally
Deliver by caesarean section

63. BREECH PRESENTATION
Occurs when the fetus is in a longitudinal lie with the buttocks or feet closest to the cervix
Incidence 3-4% of all deliveries
The presenting diameter is the bitrochanteric (10 cm)
The denominator is the sacrum

64. Predisposing factors Prematurity Uterine malformations Polyhydramnios
Placenta previa
Fetal abnormalities e.g. aneuploidy
Multiple gestations

65. Perinatal mortality is increased 2- to 4-fold with breech presentation regardless of the mode of delivery
Deaths are usually associated with malformations, prematurity, IUFD

66. Types of Breech Frank breech Occurs in 50-70%
The hips are flexed with knees and legs extended on the abdomen upto the head of the fetus

67. Frank breech

68. Complete breech
Occurs in 5-10%
The hips and knees are flexed
The fetal attitude is one of complete flexion

69. Complete breech

70. Footling or incomplete breech
Occurs in 10-30%
One or both feet present because neither hips nor knees are fully flexed
The feet are lower than the buttocks

71. Footling breech

72. Causes
Extended legs
Spontaneous cephalic version may be inhibited if the fetus lies with the legs extended
Preterm labor
Breech presentation is common before 34 weeks gestation

73. Causes cont,.d Multiple pregnancy
Limits the space available for each fetus to turn thus one or more fetuses may present by breech
Polyhydramnios
Distension of the uterine cavity by excessive amounts of amniotic fluid may cause the fetus to present by breech

74. Causes cont,.d Hydrocephaly
The increased size of the fetal head is more readily accommodated in the fundus
Uterine abnormalities
Distortion of the uterine cavity by a septum or a fibroid may result in breech presentation
Placenta previa

75. Antenatal diagnosis Abdominal examination Palpation
In primigravidae diagnosis is more difficult because of their firm abdominal muscle
The lie is normally longitudinal with a soft presentation
The head can be felt in the fundus as a round hard mass
Complains of discomfort under the ribs due to pressure of the head on diaphragm

76. Auscultation
When the breech has not passed through the pelvic brim the fetal heart is heard most clearly above the umbilicus
With legs extended breech descents into the pelvis easily making the fetal heart to be heard at a lower level

77. Diagnosis during labor
If legs are extended the breech may feel like a head abdominally and on VE if the cervix is less than 3cm dilated and the breech is still high
Abdominal examination
May be diagnosed on admission in labor

78. Vaginal examination
The breech feels soft and irregular
No sutures are palpable
Occasionally the sacrum may feel like a head and the buttocks mistaken for caput succedaneum
The anus may be felt – fresh meconium on the examining finger is diagnostic
If legs are extended the external genitalia are evident but becomes edematous
An edematous vulva may be mistaken for a scrotum

79. If a foot is felt the midwife should differentiate it from a hand
Toes are all the same in length, shorter than fingers and the big toe cannot be opposed to other toes
The foot is at a right angle to the leg and the heel has no equivalent in the hand

81. Management of labor Second stage
Confirm full dilatation of the cervix before the woman commences active pushing
Obstetrician and neonatologist should be present during the delivery

82. When the buttocks are distending the perineum, the woman is placed in lithotomy position and the vulva is swabbed and draped with sterile towels
The bladder should be empty
The woman is encouraged to push with contractions and the buttocks are delivered spontaneously
If the legs are flexed the feet disengage at the vulva and the baby is born as far as the umbilicus

84. A loop of cord is gently pulled down to avoid traction at the umbilicus
The cord should not be manipulated to avoid spasms
The midwife should feel for the elbows which are usually on the chest
The arms will escape with the next contraction

85. Delivery of the shoulders
The uterine contractions and the weight of the baby will bring the shoulders down on the pelvic floor where they will rotate in the anteroposterior diameter of the outlet
The baby should be covered with sterile towels or cotton wool to preserve warmth and improve the grip on the slippery skin
Grasp the baby by the iliac crest and should be tilted towards the maternal sacrum in order to free the anterior shoulder

92. When the anterior shoulder has escaped, the buttocks are lifted towards the maternal abdomen and to enable the posterior shoulder and arm to pass over the perineum
As the shoulders are born the head enters the pelvic brim and descents through the pelvis with the sagittal suture in the transverse diameter

93. Delivery of the head
When the back has been turned the infant is allowed to hang from the vulva without support
The weight of the baby brings the head to the pelvic floor on which the occiput rotates forwards
The sagittal suture is now in the AP diameter of the outlet
Gradually the neck elongates and the hair-line appears
Controlled delivery of the head is necessary to avoid sudden change in the intracranial pressure

94. Complications of breech delivery
Impacted breech
Cord prolapse
Birth injury
Fetal hypoxia
Premature separation of the placenta
Maternal trauma