Flashcards in Foetal Monitoring Deck (56)
Give 5 factors that may make women high-risk in labour
1. Maternal/ medical history
2. Obstetric history
3. History of pregnancy/ foetal history
4. Presenting factor
5. Features of labour
Describe intermittent auscultation
- Low-risk women
- Do not require admission CTG
- 1st stage = auscultate every 15 mins after most recent contraction for min. 60s
- 2nd stage = auscultate every 5 mins after most recent contraction for min. 60s
- If abnormalities are noted, commence continuous monitoring
What do NICE guidelines say regarding intermittent auscultation?
- Do not offer CTG to women at low risk of complications
- Use Pinard or Doppler ultrasound
- Record accelerations and decelerations
- Palpate maternal pulse if foetal HR is abnormal to differentiate between HRs
Give some pregnancy indications that continuous electronic foetal monitoring (cEFM) is required
- Previous CS
- Pregnancy >42 wks
- Induced labour
- Multiple pregnancy
What is oligohydramnios?
Deficiency of amniotic fluid
Give some labour indications that cEFM is required
- Pulse >120bpm
- BP >160/ or >/110
- BP 2x >140/ or >/90 in 30 mins (or 2+ protein in urine and >140/90)
- Oxytocin use
- Significant meconium
- Vaginal bleeding
What is a tocograph?
A pressure monitor that records uterine activity continuously
What is an ultrasound transducer?
Records the foetal heart by transmitting ultrasound waves which are then bounced off a moving object (the valves of the heart)
Name a method of internal foetal monitoring
Foetal scalp electrode
What does monitoring help prevent?
- Hypoxic Ischaemic Encephalopathy (brain injury caused by oxygen deprivation)
- Neonatal seizures
- Cerebral palsy
- Intrapartum death
How should monitoring be prepared?
- Paper speed 1cm/min
- Date and time correct
- FHR displays 50-210 used
- Tocograph basline set
- Date, time and woman's name and number written on trace
- Maternal pulse palpated simultaneously with auscultation and recorded
- Palpate, measure, pinard
Give some limitations and adverse effects of foetal monitoring
- No evidence to support it
- High false positive rate (40-60%)
- Increases risk of intervention and operative delivery
- Parental anxiety
What are the 3 groups of babies that can be classified by foetal monitoring?
1. OK - coping well with stress of labour
2. Showing stress response but coping
3. Not coping with stress response
What does the anagram MOTHERS refer to?
M - meconium
O - oxytocin
T - temperature
H - hyperstimulation/ haemorrhage
E - epidural
R - rate of progress
S - scar (previous CS)
What is significant meconium?
Green = sign of foetal distress
What does the anagram DR C BRAVADO refer to?
DR - define risk (high/low)
C - contractions (present, frequency, strength)
Bra - baseline rate (normal, bradycardia, tachycardia)
V - variability (>5bpm)
A - accelerations
D - decelerations (early, variable, late, prolonged)
O - overall (normal, suspicious, pathological) and plan
What are the 4 features that should be documented from a CTG?
1. Baseline FHR
2. Baseline variability
3. Presence/absence of decelerations
4. Presence of accelerations
What happens if the CTG cannot be interpreted?
Senior obstetric input is required
What is the baseline rate?
- Mean level of FHR over 10-15 minutes without accelerations/decelerations
- Balance between SNS and PNS
What are the 3 categories of baseline rate defined by the NICE?
1. Reassuring = 110-160bpm
2. Non-reassuring = 100-109 or 161-180bpm
3. Abnormal = >180 or <100bpm
Give some factors that may cause an abnormal bradycardia baseline
- Maternal hypotension (low BP)
- Hypertonic uterus (too many contractions
- Placental abruption
- Rapid progress
- Cord prolapse
Give some factors that may cause an abnormal tachycardia baseline
- Foetal movements
- Foetal anaemia or hypovolaemia
- Maternal pyrexia/ tachycardia
- Drugs = Ritodrine, Ventolin, Nicotine
What is baseline variability?
The degree that the baseline varies in a particular band width, excluding accelerations and decelerations (5-25bpm)
- Determined between contractions
- Normal for foetus to have periods of reduced variability
What are the 3 classifications of baseline variability defined by the NICE?
1. Reassuring - 5-25bpm
2. Non-Reassuring - <5bpm for 30-50 mins or >25bpm for 15-25 mins
3. Abnormal - <5bpm for over 50 mins or >25bpm for over 25 mins or sinusoidal (constant HR - linked with thumb sucking)
What is the most important marker of foetal wellbeing?
Baseline variability >5bpm
Give some factors that may cause reduced variability
- Paper speeds
- Sleep phase
- Congenital malformations
- Drugs (pethidine, sedatives, anti-hypertensives, anti-epileptics)
- Increase above baseline rate of 15bpm+ lasting 15 seconds+
- Presence is reassuring but absence is not necessarily concerning
- There should always be accelerations antenatally
What are decelerations?
Slowing of FHR below baseline of 15bpm+ lasting 15 seconds+
- If variability is abnormal, decelerations may be significant even if drop is <15bpm/ shallow
What are the 4 types of deceleration?
1. Early - very rarely <2% benign, nadir of deceleration matches peak of contraction, late 1st + 2nd stage
2. Late - nadir 20 seconds after peak of contraction
3. Variable - most common (85%), variable in shape, length, depth and frequency
4. Prolonged - 3 minutes+