Assessment of foetal wellbeing (CTG) Flashcards Preview

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Flashcards in Assessment of foetal wellbeing (CTG) Deck (19)

What should you ask the mother about on Hx to assess foetal wellbeing?

Foetal movements


When should a mother be able to start feeling foetal movements?

Between 18-20 weeks


1 Ex for assessing foetal wellbeing?

Symphyseal-fundal height. Length should match no. weeks gestation


Name 4 foetal biometry measurements on U/S

Head circumference
Biparietal diameter
Abdominal circumference
Femur length


What does a smaller abdominal:head ratio on foetal biometry indicate about the foetus?

It's starving!


What does the amniotic fluid index measure on U/S

Vertical depth of amniotic fluid


What is better: a flexed or extended foetus in utero?

Flexed; extension indicates illness


Name the 6 parameters that make up the biophysical profile of a foetus

Foetal body movements
Foetal breathing
Foetal HR
Amniotic fluid index
Foetal tone


What two vessels are often measured by Doppler U/S in pregnancy, and what can they show? At what stage of pregnancy are they measured? Name 3 indications to use Doppler U/S

Umbilical artery and Middle Cerebral Artery - useful in measuring foetal hypoxia. Measured in 3rd trimester.

Indications - any scenario where there's a risk of IUGR or poor perinatal outcome:

Maternal - DM, renal disease, HT
Foetal - IUGR, reduced foetal movements, oligo/polyhydramnios, multiple pregnancy


What does a CTG measure?

Variation in foetal HR over time


What are the 4 features of a CTG? What are normal values for them?

Baseline HR - 110-160bpm
Variation - 5-25bpm
Acceleration - 2x 15bpm accelerations in 20 minutes
Deceleration - none


What do increased, reduced and absent variability indicate on a CTG?

Increased - anaemia
Reduced - sleeping, sedated, sick, submature (premature)
Absent - Severe hypoxia


What does a sinusoidal pattern of variability indicate on CTG?

Severe foetal anaemia


What is an early deceleration and what does it indicate?

Deceleration simultaneous with contraction. Indicates head compression during labour


What is a late deceleration and what does it indicate?

Deceleration that peaks after peak of contraction. Indicates foetal hypoxia (already hypoxic foetus will peripherally vasoconstrict during contraction = HR will drop to maintain BP)


What is a variable deceleration and what does it indicate?

Deceleration simultaneous with contraction but with rapid onset and recovery. Indicates cord compression during late labour


What is a prolonged deceleration and what does it indicate?

Deceleration > 2 minutes. Indicates sustained hypoxia


Give 4 causes of sudden severe foetal hypoxia

Cord compression
Maternal hypotension
sustained uterine contraction
Placental abruption


What is a reactive, non-reactive and critical CTG? What should you do in each case?

Reactive = normal (normal baseline, variability, accelerations, no decelerations). Continue with intermittent CTG or auscultation.

Non-reactive = reduced variability, no accelerations. Investigate for hypoxia (Doppler U/S, biophysical profile), and start continuous CTG

Critical - late decelerations, absent variability, sinusoidal pattern. Deliver via C/S, unless cervix already fully dilated and head is low