CTG

Question 1

How to interpret a CTG (cardiotography)

Answer 1

DR C BRaVADO

• Define risk
• Contractions
• Baseline Rate
• Variability
• Accelerations
• Decelerations
• Overall impression

Question 2

Normal CTG

Answer 2

CONTRACTIONS

• strong
• last 45-60s
• every 3-4min

BASELINE RATE
110-160bpm

VARIABILITY
>5bpm

presence of ACCELERATIONS

DECELERATIONS mimic contractions

Question 3

Reasons for foetal bradycardia in CTG

Answer 3

• Gestation >40w
• Cord compression
• Congenital heart malformations
• Congenital heart block
• Drugs eg benzodiazepine

Question 4

Reasons for foetal tachycardia in CTG

Answer 4

• Excessive foetal movement
• Maternal anxiety
• Gestation <32w
• Maternal pyrexia
• Foetal infection
• Chronic hypoxia

Question 5

What does variability in a CTG indicate

Answer 5

Intact integration between CNS and heart of foetus

More wiggly line (>5) is better

Question 6

What in a CTG is the best indicator of foetal well being

Answer 6

Accelerations

Question 7

What is considered an acceleration in a CTG?

What does this indicate?

Answer 7

Increase of >15bpm above baseline for at least 15s

Indicates moving, stimulation

Question 8

What do early decelerations in a CTG indicate

Answer 8

Mirrors contraction

Question 9

What do late decelerations in a CTG indicate

Answer 9

Associated with foetal hypoxia.

Ominous if foetus has also passed meconium.

Question 10

What is considered a sinusoidal pattern in a CTG

Answer 10

Amplitude of 10bpm in cycle of 2-5 per minute. Lasts >2min

Question 11

What is a sinusoidal pattern in a CTG associated with

Answer 11

Severe foetal anaemia and hydrops

but may also occur with thumb sucking

Question 12

Maternal reasons for continuous monitoring during birth

Answer 12

• Rhesus incompatibility
• Hypertension/ PIH/ pre-eclampsia
• Diabetes
• Antepartum haemorrhage
• Epilepsy, CVS conditions, renal conditions

Question 13

Foetal reasons for continuous monitoring during birth

Answer 13

• IUGR
• oligohydramnios
• Abnormal doppler velocimetry
• Preterm
• Multiple pregnancy
• Breech pregnancy
• Pregnancy >42w
• Baby has passed meconium

Question 14

Labour reasons for continuous monitoring during birth

Answer 14

• Use of syntocinon
• VBAC
• Prolonged ROM >18-24h
• Suspicious HR on auscultation using pinnard
• Epidural insitu
• By request (age, poor obstetric history)