CTGs Flashcards
what is the role of fetal monitoring in labour
assesses fetal wellbeing and allows for the early detection of fetal distress - hypoxia
fetal monitoring in low risk labours
intermittent auscultation
fetal monitoring in high risk labours
cardiotocography (CTG)
methods of intermittent auscultation
doppler US
timings for intermittent auscultation
for 1 min after a contraction every:
- 15 mins in 1st stage
- 5mins in 2nd stage
- any abnormalities or intrapartum complications - do CTG
what does the CTG represent
autonomic and CNS activity
what are the 2 parts of CTG
fetal heart rate sensor
contraction monitor sensor
indications for CTG monitoring
induction of labour
post maturity (>42wks) or prematurity (<37wks)
multiple pregnancy
underlying maternal health conditions
antepartum/intrapartum haemorrhage
pyrexia
abnormal lie, small for gestational age, oligohydramnios
epidural
abnormalities noted on intermittent auscultation
interpretation of CTG mnemonic
DR C BRAVADO
what do the letters of DR C BRAVADO stand for
Determine Risk Contractions Baseline RAte Variability Accelerations Decelerations Overall
what do the letters of DR C BRAVADO stand for
Determine Risk Contractions Baseline RAte Variability Accelerations Decelerations Overall
DR C BRAVADO - determine risk
why is the woman having external fetal monitoring
DR C BRAVADO - Contractions
how many in 10 mins
- how many occur in 20 boxes (bottom strip)
DR C BRAVADO - baseline rate
avg fetal HR when accelerations and decelerations have been excluded
DR C BRAVADO - baseline rate, baseline bradycardia
- HR
- causes
HR <100bpm
increased fetal vagal tone
maternal beta blocker use
DR C BRAVADO - baseline rate, baseline tachycardia
- HR
- causes
> 160bpm
maternal pyrexia
chorioamnionitis
hypoxia
prematurity
DR C BRAVADO - variability
variability of baseline rate
loss of baseline variability - <5bpm
- prematurity, hypoxia
DR C BRAVADO - variability
variability of baseline rate
loss of baseline variability - <5bpm
- prematurity, hypoxia
DR C BRAVADO - accelerations
upwards spike of >15bpm for >15s
these are reassuring and occur when fetus moves
DR C BRAVADO - decelerations
downwards spike of >15bpm for >15s
may be a normal feature of labour
what are early decelerations
decelerations of HR at onset of contractions
usually caused by head compression, often seen in breech presentation
what are late decelerations
deceleration of the HR which lags the onset of contractions and doesn’t return to normal until after 30s following the end of the contraction
indicates fetal distress e.g. asphyxia, placental insufficiency
what are variable decelerations
independent of contractions
may indicate cord compression
DR C BRAVADO - overall
is this CTG normal, non-reassuring or abnormal
what is the role of fetal blood sampling
to confirm CTG signs of fetal hypoxia
responses to different fetal blood sampling pH
> 7.25 - repeat in 1hr if CTG remains abnormal
7.21-24 - repeat in 30 mins if CTG remains abnormal
<7.2 - immediate delivery, indicates hypoxia
what % of cerebral palsy cases are due to fetal hypoxia
10%
