Fetal procedures Flashcards
What is cardiotocography?
continuous monitoring of the foetal heart and uterine activity -> used in labour
What is a growth scan?
booking scan at 12 (8-14) weeks, anomaly scan at 20 (18-21) weeks -> monitor pregnancy
What is a foetal doppler?
– used to monitor FHR and should be placed over the anterior shoulder of foetus -> monitor pregnancy
What is foetal blood sampling?
blood withdrawn from umbilical vein to determine if severe anaemia caused by Rh sensitisation
What are the complications of foetal blood sampling?
Bleeding from site
Changes in FH
Infection
Leaking of amniotic fluid
Death of foetus (1%)
What do you look for on USS?
Lie and presentation (i.e. if breech, what type of breech)
Liquor volume
Placental location
Fibroids or other growths
What are the indications in labour of cardiotocography?
o Intrapartum care of normal labour
o Suspected chorioamnionitis or sepsis, or a temperature >38C
o Severe hypertension (> 160/110)
o Oxytocin use
o Presence of significant meconium
o Fresh vaginal bleeding that develops in labour
What mnemonic do you use to interpret cardiotocography?
DR C BRAVADO
What are the parts of DRCBRAVADO?
Define Risk
Contractions
BRA (Baseline Rate)
Variability
Acceleration
Decelerations
Overall impression
How do you define risk?
Why are they on a CTG monitor? Previous CTGs?
What is a normal number of contractions at labour?
5 contractions in 10 minutes
Look at each peak (5 contractions in 1 large block
What is normal baseline rate?
110-160 bpm
What is normal variability?
5-25 bpm
Most commonly <5 (≤40 minutes) due to sleeping
What is normal acceleration?
At least 2 every 15 minutes
Acceleration = rise in FHR of ≥15 bpm lasting ≥15s Occur in response to foetal movements
What is normal decelerations?
None
Deceleration = drop in FHR of ≥15 bpm lasting ≥15s Late decelerations are much worse than early decelerations
What is the overall impression?
Overall interpretation
What defines baseline bradycardia and tachycardia?
HR <110bpm
Increased foetal vagal tone
Maternal beta-blocker use
HR >160bpm
Maternal pyrexia
Chorioamnionitis
Hypoxia
Pre-maturity
What is loss of baseline variability?
<5bpm [5-25 is normal]
Hypoxia
Pre-maturity
What is early decelerations?
Commences with onset of contraction and returns to normal with completion of contraction
Head compression (innocuous)
Not of concern generally
What is late decelerations?
Lags the onset of a contraction and does not return to normal until after 30s following end of contraction
Reduced uteroplacental flow
What is variable deceleration?
Independent of contractions
Cord compression
What are indications for emergency C section in cardiotocography?
o Terminal Bradycardia: FHR < 100 bpm for more than 10 mins
o Terminal Deceleration: FHR drops and does not recover for more than 3 mins
What is the classification of CTG traces?
Normal
Non reassuring
Pathological
What is normal antenatal/ intrapartum CTG?
‘met criteria’
§ FHR: 110-160 bpm
BV: 5-25 bpm
§ Decelerations: absent or early
Accelerations: 2 within 20 mins
What is non reassuring CTG?
§ 100-110 bpm or 161-180 bpm
§ BV: <5 for 30-50 mins or >25 for 15 mins
§ Variable decelerations with:
· no other concerning characteristics, for >90 mins
· <50% of contractions for >30 mins
· >50% of contractions for <30 mins
§ Late decelerations in >50% of contractions for <30 min
What is pathological CTG?
athological CTG:
§ Sinusoidal rhythm -> IMMEDIATE CAT 1 EMCS
· Severe foetal anaemia or hypoxia
· Foetal or maternal haemorrhage
§ <100 bpm or >180 bpm
§ Late decelerations >30 mins = maternal hypotension, pre-eclampsia, uterine hyperstimulation
§ BV: <5 for >50 mins, >25 for >25 mins, sinusoidal
§ Variable decelerations with any concerning characteristics in >50% contractions for <30 mins
§ Acute bradycardia or a single prolonged deceleration lasting >3 mins (terminal bradycardia)
What do you do if the CTG is borderline?
If the CTG is borderline, you could do foetal blood sampling to check for acidosis (pH <7.2)
§ Acidosis is a LATE marker of reduced oxygen delivery
What is uterine hyperstimulation?
§ Single contraction >2 mins duration
§ 5 or more contractions in 10 mins
How do you do an overall interpretation?
§ Normal -> all features are reassuring
§ Suspicious -> 1 non-reassuring AND 2 reassuring features
§ Pathological -> 1 abnormal OR 2 non-reassuring features
What are the types of decelerations?
Uniform
Early
Late
Variable
Combined
What is uniform decelerations?
squeezing the baby’s head causes a baroreceptor reflex leading to a uniform deceleration
What is early decelerations?
common in the 2nd stage, and should recover by the end of the contraction
What is late decelerations?
PATHOLOGICAL -> do foetal blood sampling:
§ If foetal pH >7.2 -> normal -> continue monitoring
§ If foetal pH <7.2 -> foetal acidosis -> urgent delivery
What is variable decelerations?
cord prolapse, cord compression (of any kind)
§ “Shoulders of deceleration” = accelerations before and after variable deceleration = not yet hypoxic
What is combined decelerations?
when you get a deceleration within a deceleration due to an overactive uterus
§ This may be caused by bleeding, infection or overzealous use of syntocinon
§ There should be at least 1 minute between contractions to allow the baby to recover
How do you manage a non reassuring CTG?
§ (1) Left lateral position
§ (2) Stop oxytocin / consider tocolysis
· Exclude acute event (e.g. cord prolapse, uterine rupture)
· Correct underlying causes
· Give fluids (IV or oral)
§ (3) Digital foetal scalp stimulation (accelerates the heartbeat
How do you manage a pathological CTG?
§ (1) Left lateral position
§ (2) Stop oxytocin / consider tocolysis
· Exclude acute event (e.g. cord prolapse, uterine rupture)
· Correct underlying causes
· Give fluids (IV or oral)
§ (3) Digital foetal scalp stimulation (accelerates the heartbeat
§ (4) Foetal blood sampling (if not possible, expedite birth)
§ (5) EMCS
What is this:
Variable decelerations
