CTG Flashcards
How to interpret a CTG (cardiotography)
DR C BRaVADO
- Define risk
- Contractions
- Baseline Rate
- Variability
- Accelerations
- Decelerations
- Overall impression
Normal CTG
CONTRACTIONS
- strong
- last 45-60s
- every 3-4min
BASELINE RATE
110-160bpm
VARIABILITY
>5bpm
presence of ACCELERATIONS
DECELERATIONS mimic contractions
Reasons for foetal bradycardia in CTG
- Gestation >40w
- Cord compression
- Congenital heart malformations
- Congenital heart block
- Drugs eg benzodiazepine
Reasons for foetal tachycardia in CTG
- Excessive foetal movement
- Maternal anxiety
- Gestation <32w
- Maternal pyrexia
- Foetal infection
- Chronic hypoxia
What does variability in a CTG indicate
Intact integration between CNS and heart of foetus
More wiggly line (>5) is better
What in a CTG is the best indicator of foetal well being
Accelerations
What is considered an acceleration in a CTG?
What does this indicate?
Increase of >15bpm above baseline for at least 15s
Indicates moving, stimulation
What do early decelerations in a CTG indicate
Mirrors contraction
What do late decelerations in a CTG indicate
Associated with foetal hypoxia.
Ominous if foetus has also passed meconium.
What is considered a sinusoidal pattern in a CTG
Amplitude of 10bpm in cycle of 2-5 per minute. Lasts >2min
What is a sinusoidal pattern in a CTG associated with
Severe foetal anaemia and hydrops
but may also occur with thumb sucking
Maternal reasons for continuous monitoring during birth
- Rhesus incompatibility
- Hypertension/ PIH/ pre-eclampsia
- Diabetes
- Antepartum haemorrhage
- Epilepsy, CVS conditions, renal conditions
Foetal reasons for continuous monitoring during birth
- IUGR
- oligohydramnios
- Abnormal doppler velocimetry
- Preterm
- Multiple pregnancy
- Breech pregnancy
- Pregnancy >42w
- Baby has passed meconium
Labour reasons for continuous monitoring during birth
- Use of syntocinon
- VBAC
- Prolonged ROM >18-24h
- Suspicious HR on auscultation using pinnard
- Epidural insitu
- By request (age, poor obstetric history)
