Cardiotocography

Question 1

what is it?

Answer 1

pressure changes in the uterus using internal or external pressure transducers

Question 2

what is a normal foetal heart beat?

Answer 2

normal fetal heart rate varies between 100-160 / min

Question 3

what is categorised as baseline bradycardia

Answer 3

< 100 bpm

Question 4

what are the causes of baseline bradycardia?

Answer 4

Increased fetal vagal tone,

maternal beta-blocker use

Question 5

baseline tachycardia and causes

Answer 5

Heart rate > 160 /min

Maternal pyrexia, chorioamnionitis, hypoxia, prematurity

Question 6

loss of baseline variability

Answer 6

< 5 beats / min

Prematurity, hypoxia

Question 7

early deceleration

Answer 7

Deceleration of the heart rate which commences with the onset of a contraction and returns to normal on completion of the contraction

causes: Usually an innocuous feature and indicates head compression

Question 8

late deceleration

Answer 8

Deceleration of the heart rate which lags the onset of a contraction and does not returns to normal until after 30 seconds following the end of the contraction

indicates fetal distress e.g. asphyxia or placental insufficiency

Question 9

variable decelerations

Answer 9

Independent of contractions

May indicate cord compression