MALPRESENTATION IN LABOUR

Question 1

What do we mean by malpresentation towards the end of pregnancy?

Answer 1

Any presentation other than a vertex presentation.

Question 2

What is the vertex in terms of presentation of the fetus?

Answer 2

The vertex is the area between parietal eminences and the anterior and posterior fontanelles. The fetus will have its neck flexed with its chin tucked into its chest.

Question 3

What are the different types of malpresentation?

Answer 3

Breech

Shoulder

Face

Brow

Transverse

Question 4

What are the maternal causes and risk factors of malpresentation?

Answer 4

Contraction of the pelvis

Pelvic tumour eg fibroid

Mullerian abnormality

Multiparity

Question 5

What are the fetoplacental causes and risk factors of malpresentation?

Answer 5

Prematurity

Placenta praevia

Polyhydramnios

Multiple pregnancy

Fetal abnormality

Fetal anomaly:
Hydrocephalus
Extension of fetal head by neck tumours
Anencephaly
Decreased fetal tone

Question 6

What is the most common type of malpresentation?

Answer 6

Breech

Question 7

What is the most important risk factor for breech presentation?

Answer 7

Prematurity

Question 8

What is the incidence of breech presentation in term babies?

Answer 8

3%

Question 9

What is the incidence of breech presentation in babies who are born at 32 weeks?

Answer 9

15%

Question 10

What is the incidence of breech presentation in babies who are born at 28 weeks?

Answer 10

25%

Question 11

What are the three main types of breech presentation? Describe each one.

Answer 11

Extended or frank breech presentation - hips are flexed and the knees are extended with feet situated adjacent to the head.

Flexed or complete breech presentation - flexion at both the hips and knees with feet at same level as breech

Footline breech presentation - flexion at both hips and knees but with feet present to the maternal pelvis not the breech

Question 12

What is the most common type of breech presentation?

Answer 12

Extended or frank breech - 50%

Question 13

If there is doubt about malpresentation from palpation what should be done for the patient?

Answer 13

Ultrasound to confirm

Question 14

What are the complications associated with breech presentations at labour?

Answer 14

Increased perinatal mortality and morbidity - usually associated with delivering the head once the rest has delivered.

Intracranial injury - no time for head moulding as head will compress cord

Hypoxic-ischemic encephalopathy

Cord prolapse

Spinal cord injury

Adrenal haemorrhage

Fractures of clavicle or humerus

Question 15

What is a nuchal arms delivery?

Answer 15

This is when the arms get trapped up along with the head and allows for even less space through the pelvis.

Question 16

What are the three management options for a breech presentation?

Answer 16

External cephalic version (ECV)

Elective caesarian section

Planned vaginal breech delivery

Question 17

What is external cephalic version?

Answer 17

This is an attempt to turn the baby inside the womb to cephalic presentation, by massaging the fetus first into transverse lie and then rolling over into the cephalic presentation.

Question 18

When should external cephalic version be attempted?

Answer 18

At 37 weeks.

Question 19

What are the contraindications to external cephalic version.

Answer 19

Pelvic masses

Antepartum haemorrhage

Placenta praevia

Previous caesarian section or hysterotomy

Multiple pregnancy

Ruptured membrane

Question 20

What medications should be given if external cephalic version is to be attempted?

Answer 20

Tocolytics can be used to reduce uterine activity

Anti-D should be given if mother is rhesus negative

Question 21

What measures should be taken if the mother decides to proceed with a vaginal breech delivery?

Answer 21

Check estimated fetal weight - above 4kg should indicate caesarian section

Continuous fetal heart measurement

Must exclude cord prolapse when membranes rupture or if fetal heart rate becomes abnormal

Epidural anaesthesia is recommended because of increased manipulation required.

Routine episiotomy

Question 22

What is the success rate of vaginal breech delivery?

Answer 22

About 50% as there is such a low threshold for doing caesarian section that most will never get far enough.

Question 23

What is Lovset’s manoeuvre?

Answer 23

This is a manoeuvre performed to keep the spine anterior and aims to reduce the incidence of nuchal arms.

Question 24

What is the Mauriceau-Smellie-Veit manoeuvre?

Answer 24

Improves flexion of head to allow easier delivery.

Question 25

What is the definition of unstable lie?

Answer 25

This is when, after 37 weeks, the fetal lie is found to be in a different orientation at each palpation.

Question 26

What is the incidence of transverse lie in labour?

Answer 26

1 in 500

Question 27

What should you check before doing a vaginal examination of a patient with a fetus in transverse lie?

Answer 27

Placenta praevia should be excluded

Question 28

What risk factors particularly increase the likelihood of the fetus being in transverse lie at labour?

Answer 28

Multiparity - reduced tone of uterus Premature labour The second twin is more likely to be in transverse lie

Question 29

What is the most serious complication of transverse lie?

Answer 29

Cord prolapse

Question 30

How do you manage someone who presents with transverse or unstable lie after 37 weeks?

Answer 30

Exclude cause of malpresentation such as placenta praevia ECV can be attempted if no such cause is found and as long as membranes have not ruptured If reversion to malpresentation occurs or an unstable lie is diagnosed then admission to hospital from 37 weeks is indicated when immediate delivery is possible if membranes rupture. At term, unstable lie can spontaneously vert to cephalic presentation and this can be managed normally. ECV followed by immediate induction of labour and artificial rupture of membrane may work If not caesarian section is indicated

Question 31

What is face presentation?

Answer 31

This is when the fetus extends their neck and head rather than flexing.

Question 32

What is the incidence of face presentation?

Answer 32

1 in 300

Question 33

What are the risk factors for face presentation?

Answer 33

Congenital tumour of the neck | Anencephaly

Question 34

What is the name and diameter of the widest part of the skull during face presentation?

Answer 34

Submento-bregmatic - 9.5 cm

Question 35

When is diagnosis of face presentation usually made?

Answer 35

Vaginal examination in labour, when supraorbital ridges, bridge of the nose and mouth are palpable

Question 36

Why is face presentation sometimes initially misdiagnosed as breech presentation?

Answer 36

The face become oedematous

Question 37

With reference to the chin, what position must the fetus be lying in for vaginal delivery to be successful if face presentation is diagnosed?

Answer 37

Mentoanterior position Mentoposterior position will not work as the head will not be able to be flexed.

Question 38

How do we manage face presentation at labour?

Answer 38

Check that it is mentoanterior - initial mentoposterior presentation will spontaneously rotate to mentoanterior presentation in 50% of cases. If mentoanterior - essentially the same as vertex presentation. Forceps can be used to correct delay. If mentoposterior and not rotating - caesarian section If fetal heart abnormalities, proceed to caesarian section as FBS should not be taken from face.

Question 39

What is brow presentation in labour?

Answer 39

When the forehead and top of the head engage in the pelvis without head flexion. There is slight extension of the neck but not to the same degree as face presentation.

Question 40

What is the incidence of brow presentation?

Answer 40

1 in 500

Question 41

What are the risks and complications of presentation?

Answer 41

Early rupture of the membranes Cord prolapse

Question 42

What is the name and diameter of the widest part of the skull during brow presentation?

Answer 42

Submento-vertical - 13.5 cm

Question 43

How do we manage patients with brow presentation?

Answer 43

Labour should be monitored but allowed to continue as extension to face presentation or flexion to vertex presentation are the most common outcomes. Any failure to progress or fetal distress should lead to c-section.