Management of Labour

Question 1

What are the indications for induction of labour?

Answer 1

Prolonged pregnancy (>42 weeks)
Pre-eclampsia
Placental insufficiency + IUGR
Antepartum haemorrhage
Rhesus isoimmunisation
Diabetes
CKD

Question 2

How can the likely outcome of induction of labour be predicted?

Answer 2

Assessment of the cervix –> Bishop’s score

Question 3

What are the components of the Bishop’s score?

Answer 3

Dilatation (cm)
Effacement (%)
Station
Cervical consistency
Cervical position

Question 4

How is the Bishop’s score interpreted?

Answer 4

Score of 0, 1, 2, or 3 for each component

Total score > 6 is strongly predictive of labour following induction
Score < 5 indicates need for cervical ripening

Question 5

What are the different options for induction of labour?

Answer 5

Stripping of membranes (sweep)
Artificial rupture of membranes using amniotomy
Medical induction with syntocinon infusion (following amniotomy)
Medical induction + cervical ripening with prostaglandin E2 pessary
Mechanical cervical ripening (balloon catheter)

Question 6

What are the requirement for undertaking artificial rupture of membranes?

Answer 6

Cervix - soft, effaced + at least 2cm dilated

Head should be engaged in the pelvis and should be presenting by the vertex

Question 7

What is syntocinon and what are the risks of giving it?

Answer 7

Synthetic oxytocin

- uterine hyperstimulation (>5 contractions in 10 minutes) reduces blood flow to foetus

Question 8

What are the risks of using prostaglandins for induction?

Answer 8

Hyperstimulation + uterine rupture

–> contraindicated in those with previous uterine scar

Question 9

What is a partogram and what is included in it?

Answer 9

Graphic representation of maternal + foetal data during labour:

• foetal HR
• cervical dilatation
• duration of labour
• colour of liquor
• frequency + duration of contractions
• caput + moulding
• station/descent of head
• maternal HR, BP + temperature

Question 10

How is the descent of the head recorded?

Answer 10

Station –> level of the presenting part in cm above or below the ischial spine
+1, +2 or +3 if below spines
-1, -2 or -3 if above spines

Question 11

Which pain killers can be used in labour?

Answer 11

Opiates:
- pethidine, morphine or remifentanil

Entonox (50:50 nitrogen + oxygen) - inhaled

Question 12

What are the side effects of taking opiates in labour?

Answer 12

Nausea + vomiting –> given with antiemetic

Foetal respiratory depression (especially if taken within 2 hours of delivery)

Question 13

What are the options for regional analgesia in labour?

Answer 13

Epidural

Pudendal nerve block

Question 14

How does an epidural work?

Answer 14

Fine catheter inserted into lumbar epidural space (L3-L4) and a local anaesthetic agent e.g. bupivacaine is injected
Opioid is often added to reduce the dose requirement of bupivacaine, which spares the motor fibres so women can still stand up

Question 15

What are the negative effects of having an epidural during labour?

Answer 15

May reduce the desire to bear down + reduce uterine activity
Increased risk of assisted vaginal delivery
Abnormal foetal HR –> must monitor with CTG
Hypotension
Accidental dural puncture
Postural headache
High block –> respiratory depression
Atonic bladder

Question 16

When is a pudendal block most often used?

Answer 16

For operative vaginal delivery

Question 17

How does a pudendal block work?

Answer 17

Injection of local anaesthetic around nerve at the level of the ischial spine

Question 18

What are the negative effects of a pudendal nerve block?

Answer 18

Risk of haemorrhage from pudendal artery
Risk of lignocaine toxicity if injected intravascularly
Can be ineffective

Question 19

When is spinal anaesthesia used?

Answer 19

Operative delivery

Question 20

Why is spinal anaesthesia not used for pain control in labour?

Answer 20

Epidural is safer + has the ability to top up with suitable doses to allow pain relief over a long period of time

Question 21

How is a spinal anaesthesia performed?

Answer 21

Catheter placed at L3-L4 and inserted into the subarachnoid space where anaesthetic is injected

Question 22

Which layers are passed through during insertion of an epidural?

Answer 22

Skin –> subcutaneous fat –> supraspinous ligament –> interspinous ligament –> ligamentum flavum –> epidural space

Question 23

Which layers are passed through during a spinal anaesthetic?

Answer 23

Skin
Subcutaneous fat
Supraspinous ligament
Interspinous ligament
Liamentum flavum
Dura mater
Sub dural space
Arachnoid mater
Subarachnoid space

Question 24

What is the pneumonic for interpreting CTGs?

Answer 24

DR - define risk
C - contractions
BRA - baseline rate
V - variability 
A - accelerations
D - decelerations
O - overall impression

Question 25

How should contractions be interpreted on the CTG?

Answer 25

Peaks at the bottom of the trace

–> in established labour, should be 3-5 contractions in 10 minutes

Question 26

How should baseline rate be interpreted on the CTG?

Answer 26

Should be about 110-160bpm

• < 110 is bradycardia
• > 160 is tachycardia

Question 27

How should variability be interpreted on the CTG?

Answer 27

Good variability is 5-15 bpm
Reduced variability is < 5bpm
Can be reduced due to foetal sleep but shouldn’t last > 40 mins
Reduced variability for > 90 minutes is abnormal

Question 28

What do accelerations show on the CTG?

Answer 28

Rise in foetal HR for at least 15bpm lasting for > 15 seconds
Associated with foetal movements - sign that baby is healthy
Should be 2 separate accelerations every 15 minutes, occurring with contractions

Question 29

What do decelerations show on the CTG?

Answer 29

Reductions in foetal HR by at least 15bpm for at least 15 seconds
- abnormal –> senior review

Question 30

Which type of decelerations would be suggestive of foetal hypoxia?

Answer 30

Late (after contraction) decelerations which are slow to recover

Question 31

Which two features make up a pre-terminal CTG and what is the management?

Answer 31

Terminal bradycardia (baseline < 100bpm for > 10 mins)
Terminal deceleration (HR drops and does not recover for > 3 mins)

–> emergency C-section

Question 32

Which investigation can be done if suspicious features are seen on the CTG?

Answer 32

Foetal scalp blood sampling (looking for acidosis)

Question 33

If a pregnant women collapses and requires CPR, when should delivery of the baby be considered?

Answer 33

If cardiac output not restored after 3 minutes of CPR –> C-section

Question 34

What should be done if the placenta has not yet been delivered 30 mins after birth of the foetus?

Answer 34

IM syntocinon + breastfeeding

Observe for another 30 mins (1 hour total)

Question 35

What are the indications for an operative vaginal delivery?

Answer 35

Inadequate progress
Maternal exhaustion
Maternal medical condition that means active pushing should be limited
Suspected foetal compromise
Clinical concerns e.g. antepartum haemorrhage

Question 36

What are the risks associated with ventouse delivery?

Answer 36

Lower success rate than forceps
(but less perineal injury and less pain)
Cephalhaematoma
Subgaleal haematoma
Foetal retinal haemorrhage

Question 37

What are the risks associated with forceps delivery?

Answer 37

Higher rate of 3rd/4th degree tears

Question 38

What are the requirements for instrumental delivery?

Answer 38

Fully dilated
Ruptured membranes
Cephalic foetal presentation
Defined foetal position
Foetal head at least at the level of ischial spines + no more than 1/5 palpable in abdomen
Empty bladder
Adequate pain relief

Question 39

What are the absolute contraindications for ventouse delivery?

Answer 39

Preterm < 34 weeks

High likelihood of foetal coagulation disorder

Question 40

What are the indications for elective C-section?

Answer 40

Breech or other malpresentation 
Twins id first twin not cephalic
Maternal conditions e.g. cardiomyopathy
Foetal compromise e.g. growth restriction
Transmissible disease e.g. uncontrolled HIV
Primary genital herpes in 3rd trimester
Placenta praevia
Maternal DM with foetal weight > 4.5kg
Previous major shoulder dystocia
Previous 3rd/4th degree tear
Maternal request

Question 41

Which layers are cut/torn through in a C-section?

Answer 41

Skin (Pfannensteil incision)
Camper's fascia
Scarpa's fascia
Rectus sheath
Rectus muscle
Parietal peritoneum 
Visceral peritoneum
Uterus (lower uterine segment)