CTG Interpretation

Question 1

What is the DR C BRaVADO systematic approach?

Answer 1

Determine Risk (maternal and fetal risk factors)
Contractions (frequency, duration, strength)
Baseline Rate (110-160 bpm normal)
Variability (5-25 bpm normal)
Accelerations (reassuring feature)
Decelerations (type and significance)
Overall impression (normal / suspicious / pathological)

Question 2

Define the normal parameters of a CTG

Answer 2

Baseline - 100-160bpm
Variability 5-25bpm
Accelerations - Present (≥15 bpm for ≥15 sec)
None or early decelerations

Question 3

What are the concerning characteristics of variable decelerations?

Answer 3

Duration >60 seconds
Reduced variability within the deceleration
Slow recovery to baseline
Failure to return to baseline
Absence of shouldering (pre/post acceleration)
Late component (deceleration continues after contraction ends)
Biphasic (W-shape) deceleration

Question 4

What are the causes of fetal tachycardia (>160 bpm)?

Answer 4

Maternal fever / chorioamnionitis (most common)
Fetal hypoxia
Maternal dehydration
Maternal anxiety / pain
Drugs (beta-agonists — terbutaline, salbutamol)
Fetal arrhythmia
Fetal anaemia
Hyperthyroidism

Question 5

What are the causes of fetal bradycardia (<110 bpm)?

Answer 5

Cord compression / prolapse
Prolonged uterine contraction (hyperstimulation)
Maternal hypotension (post-epidural)
Epidural top-up
Placental abruption
Uterine rupture
Rapid fetal descent
Fetal head compression (second stage — may be physiological)
Prolonged >3 min = emergency → prepare for immediate delivery