CTG

Question 1

Antenatal risk factors

Answer 1

Abnormal antenatal CTG
Abnormal Doppler
IUGR
Oli or poly
>42/40
Multiple 
Breech
APH
PROM
Known fetal abnormality
Uterine scar
HTN or PET
DM or macrosomia
Medical conditions
Reduced fm
BMI >40
Mat age >42
Low Papp-A

Question 2

Intrapartum risk factors

Answer 2

Iol
Abnormal auscultation
Oxy augment
Regional anaesthesia
Abnormal bleeding
Fever >38
NEC or blood stained liquor
Absent liquour following ARM
Prolonged first or second sage
PTL
Tachysystole
Uterine hypertonic
Uterine hyperstimulation

Question 3

Tachysystole

Answer 3

More than five active labour contractions in ten minutes without fetal heart rate abnormalities

Question 4

Uterine hypertonus

Answer 4

Contractions lasting more than two minutes or occurring within 60 seconds of each other, without FHR abnormalities

Question 5

Uterine hyperstimulation

Answer 5

Tachysystole or uterine hypertonus with FHR abnormalities

Question 6

Auscultation in labour (intermittent)

Answer 6

Commence toward the end of a contraction and be continued for at least 30-60 seconds after the contraction has finished

Should be done every 15-30minutes in the active phase of first stage
After each contraction or at least every five minutes in the active second stage of labour

Question 7

Contraindications to FBS

Answer 7

Evidence of serious, sustained fetal compromise
Fetal bleeding disorder
Face or brow presentation
Maternal infection

Question 8

Consider CTG when multiple factors present

Answer 8

41+
GT HTN
GDM without complications
BMI30-40
Mat age >40
Maternal pyrexia 37.8-<38

Question 9

Baseline FHR

Answer 9

Mean level of the FHR when this is stable, excluding accelerations and decelerations and contractions; determined over a time period of five or 10min and expressed in bpm; pretermers have higher

Question 10

Baseline variability

Answer 10

Minor fluctuations in baseline FHR. Assessed by estimating the difference in bpms between the highest peak and lowest rough of fluctuation in one minute segments of the trace between contractions

Question 11

Sinusoids

Answer 11

A regular oscillation of the baseline FHR resembling a sine wave. Smooth, undulating, persistent, relatively fixed period of 2-5 cycles per minute and an amplitude of 5-15bpm above and below the baseline. Baseline variability is absent and there are no accelerations

Question 12

Accelerations

Answer 12

Transient increases in FHR of 15bpm or more above the baseline and lasting 15 seconds. Accelerations in the preterm fetus may be of lesser amplitude and shorter duration.

Question 13

Decelerations

Answer 13

Transient episode of decrease FHR below the baseline of more than 15bpm lasting at least 15 seconds

Question 14

Early decels

Answer 14

Uniform, repetitive decrease of FHR with slow onset early in the contraction and slow return to baseline by the end of the contraction

Question 15

Variable decels

Answer 15

Repetitive or intermittent decreasing of FHR with rapid onset and recovery. Time relationships with contraction cycle may be variable but most commonly occur simultaneously with contractions

Question 16

Complicated variables

Answer 16

(Increase likelihood of fetal hypoxia
Rising BR or fetal tachy
Reducing baseline variability
Slow return to baseline fhr after the end of the contraction
Large amplitude(by 60bpm or to 60bpm) and/or long duration (60 seconds)
Presence of smooth post decelearation overshoots

Question 17

Prolonged decels

Answer 17

FHR below the baseline for >90 secs but less than five minutes

Question 18

Late decels

Answer 18

Uniform, repetitive decreasing FHR w usually slow onset mid to end of the contraction and nadir more than 20 seconds after the peak of the contraction and ending after the contraction.
In the presence of a non-accelerator trace with baseline variability <5bpm, the definition would include decelerations of <15bpm