Foetal Procedures

Question 1

What are the indications for foetal blood sampling?

Answer 1

Blood withdrawn from umbilical vein to determine if severe anaemia caused by Rh sensitisation

Question 2

What are the complications of foetal blood sampling?

Answer 2

• Bleeding from site
• Changes in FH
• Infection
• Leaking of amniotic fluid
• Death of foetus (1%)

Question 3

What are the indications for a CTG in labour?

Answer 3

• Intrapartum care of normal labour
• Suspected chorioamnionitis or sepsis, or a temperature >38C
• Severe hypertension (> 160/110)
• Oxytocin use
• Presence of significant meconium
• Fresh vaginal bleeding that develops in labour
• Previous anti-D rhesus reaction

Question 4

What are the normal ranges for a CTG?

Answer 4

Question 5

What are the causes of baseline bradycardia (<110bpm) on CTG?

Answer 5

• Increased foetal vagal tone
• Maternal beta-blocker use
• Prolonged cord compression
• CSE
• Maternal seizures
• Rapid foetal decent

Question 6

What are the causes of baseline tachycardia (<160bpm) on CTG?

Answer 6

• Maternal pyrexia
• Chorioamnionitis
• Hypoxia
• Pre-maturity
• Foetal tachyarrhythmia

Question 7

What are the causes of reduced baseline variability (<5bpm) on CTG?

Answer 7

• Hypoxia
• Pre-maturity (<28 weeks)
• Congenital cardiac abnormalities
• Foetal tachycardia
• Drug – opiates, benzo, Mg

Question 8

What are the causes of early decelerations on CTG?

Answer 8

• Head compression (innocuous)
• Generally not concerning

Question 9

What are the causes of late decelerations on CTG?

Answer 9

• Reduced uteroplacental flow
  
  • Maternal hypotension
  • Pre-eclampsia
  • Uterine hyperstimulation

Question 10

What are the causes of variable decelerations on CTG?

Answer 10

• Cord compression

Question 11

What are the CTG indications for an emergency C-section?

Answer 11

• Terminal Bradycardia - FHR < 100 bpm for more than 10 mins
• Terminal Deceleration - FHR drops and does not recover for more than 3 mins
• Sinusodial rhythm

Question 12

What are the criteria for a ‘met criteria’ CTG?

Answer 12

• FHR: 110-160 bpm
• BV: 5-25 bpm
• Decelerations: absent or early
• Accelerations: 2 within 20 mins

Question 13

What are the criteria for a ‘suspicious’ CTG?

Answer 13

• 1 non-reassuring feature
  
  • 100-110 bpm or 161-180 bpm
  • BV: <5 for 30-50 mins or >25 for 15 mins
  • Variable decelerations with:
    
    • For >90 mins
    • <50% of contractions for >30 mins
    • >50% of contractions for <30 mins - commonly due to hyperstimulation
    • Late decelerations in >50% of contractions for <30 mins

Question 14

What are the criteria for a ‘suspicious’ CTG?

Answer 14

• 1 abnormal or 2 non-reassuring
  
  • Sinusoidal rhythm → immediate CAT 1 EMCS
    
    • Severe foetal anaemia or hypoxia
    • Foetal or maternal haemorrhage
  • <100 bpm or >180 bpm
  • Late decelerations >30 mins = maternal hypotension, pre-eclampsia, uterine hyperstimulation
  • BV: <5 for >50 mins, >25 for >25 mins, sinusoidal
  • Variable decelerations with any concerning characteristics in >50% contractions for <30 mins
  • Acute bradycardia or a single prolonged deceleration lasting >3 mins (terminal bradycardia)

Question 15

What are the signs of uterine hyperstimulation?

Answer 15

• Single contraction >2 mins duration
• 5 or more contractions in 10 mins

Question 16

What is the management of late decelerations on CTG? in labour?

Answer 16

• PATHOLOGICAL → Foetal blood sampling
  
  • If foetal pH >7.2 = normal → continue monitoring
  • If foetal pH <7.2 = foetal acidosis → urgent delivery

Question 17

What is the management of non-reassuring/suspicious CTG?

Answer 17

• Left lateral position
• Stop oxytocin + consider tocolysis
  
  • Exclude acute event - cord prolapse, uterine rupture etc
  • Correct underlying causes
  • Give fluids
• Digital foetal scalp stimulation - accelerates the heartbeat

Question 18

What is the management of pathological CTG?

Answer 18

• Foetal blood sampling - if not possible → expedite birth
• EMCS