OSCE

Question 1

Causes of fetal tachycardia [5]

Answer 1

Foetal hypoxia

Chroioamnionitis

Hyperthyroidism

Foetal/ maternal anaemia

Foetal tachyarrhythmia

Question 2

Foetal tachycardia is defined as…

Answer 2

Baseline HR >160bpm

Question 3

Foetal bradycardia is defined as…

Answer 3

Baseline HR <110

Question 4

Normal causes of foetal bradycardia (HR =100-120)

Answer 4

Post-date gestation

Occiput posterior/ transverse presentation

Question 5

Causes of prolonged severe foetal bradycardia

Answer 5

Prolonged cord compression

Cord prolapse

Epidural/ spinal anaesthesia

Maternal seizure

Rapid foetal descent

Question 6

Reassuring variability in a CTG is…

Answer 6

Variation of foetal HR 5-25 bpm

Question 7

Non-reassuring variability in CTG is…

Answer 7

< 5bpm for 30-50 mins

> 25 bpom for 15-25 mins

Question 8

Abnormal variability in CTG is…

Answer 8

<5 bpm for >50 mins

> 25 bpm for >25 mins

Question 9

Causes of reduced variability in CTG

Answer 9

Foetal sleeping (when <40mins)

Foetal acidosis (hypoxia)- present with late decelerations

Foetal tachycardia

Drugs

Early gestation (<28 weeks)

Congenital heart problems.

Question 10

Drugs that can caused reduced variability on CTG

Answer 10

Opiates

Benzos

Methyldopa

Magnesium sulphate

Question 11

Accelerations in CTG describes…

Answer 11

Abrupt increase in baseline HR

• > 15bpm
• > 15 seconds.

They normally occur with uterine contractions

Question 12

Decelerations in CTG describes…

Answer 12

Abrupt decrease in baseline HR

• > 15bpm
• > 15 seconds

Question 13

Early decelerations in CTG describes…

Answer 13

When deceleration starts at the start of contraction and finishes at the end of contraction ends.

Question 14

Early decelerations in CTG occurs due to…

Answer 14

Increased ICP from increased vaginal tone

- Physiological

Question 15

Variable decelerations in CTG describes…

Answer 15

Decelerations with variable recovery phase

- No relation to contractions.

Question 16

Causes of variable decelerations

Answer 16

Physiological
- Labour (if no other abnormal characteristics for <90 mins)

Pathological
- Umbilical cord compression (reassuring if there are shoulders of acceleration)

Oligohydroaminos

Question 17

Late decelerations in CTG describes…

Answer 17

When decelerations begin at the peak of uterine contractions and recover after contraction ends
- Due to poor blood flow to uterus and placenta

Question 18

Causes of late decelerations

Answer 18

Maternal hypotension

Pre-eclampsia

Uterine hyperstimulation

Question 19

A prolonged deceleration lasts longer than…

Answer 19

2 mins

Question 20

A non-reassuring prolonged deceleration lasts…

Answer 20

2-3 mins

Question 21

An abnormal prolonged deceleration lasts…

Answer 21

> 3 mins

Question 22

Features of a sinusodial CTG pattern

Answer 22

Smooth, regular waves

2-5 Hz/ cycle

Stable baseline rate

No beat to beat variability

Question 23

Associations of sinusodial CTG pattern

Answer 23

Severe foetal hypoxia

Severe foetal anaemia

Foetal/ maternal haemorrhage

Question 24

Non-reassuring decels features in CTG

Answer 24

Variable decels

• No other concerning feature >90 mins
• Concerning features in <50% contractions for 30mins +
• Concerning features in >50% contractions for <30mins

Late decels
- >50% contractions, <30 mins, no risk factors

Question 25

Abnormal decels features in CTG

Answer 25

Variable decels

• Clinical concerning risk factors
• > 50% contractions
• 30 mins

Late decels
- 30 mins

Acute bradycardia

Deceleration > 3mins