CTG

Question 1

Define normal/reassuring CTG (6)

Answer 1

baseline

• 110-160 bpm

baseline variability:

• 5 - 25 bpm

Decelerations:

• none OR
• early OR
• variable decelerations with no concerning characteristics ( > 60 seconds, reduced baseline variability within deceleration, failure to return to baseline, biphasic W shape, no shouldering) for < 90 mins

+/- accelerations

Question 2

Define non-reassuring CTG (8)

Answer 2

baseline:

• 161- 180 OR,
• 100-109 bpm

variability:

• <5 for 30-50 mins OR,
• > 25 for 15-25 minutes

Decelerations:

• variable with no concerning characteristics (>60 seconds, reduced baseline variability within the deceleration, failure to return to baseline, biphasic W shape, no shouldering) 90 mins or more or
• variable with any concerning characteristics in up to 50% of contractions 30 mins or more or
• variable with any concerning characteristics in over 50% of contractions for < 30 mins or
• late in over 50% of contractions for < 30 mins, without maternal / foetal clinical risk factors eg vaginal bleeding, significant meconium

ACCORDING TO NICE GUIDELINES 2017

Question 3

Define abnormal CTG categories (8)

Answer 3

baseline

• <100 or
• > 180

baseline variability:

• < 5 for > 50 mins or
• > 25 for > 25 mins or
• sinusoidal

Decelerations:

• late for 30 mins, or less if any maternal / foetal clinical risk factors OR
• acute bradycardia: single prolonged deceleration 3 mins or more OR
• variable decelerations with any concerning characteristics ( > 60 seconds, reduced baseline variability within deceleration, failure to return to baseline, biphasic W shape, no shouldering) in > 50% contractions for 30 minutes, or less if any maternal or foetal clinical risk factors eg vaginal bleeding, significant meconium

Question 4

How determine if abnormal ctg? (2)

Answer 4

• 2 or more non reassuring or
• 1 abnormal category

Question 5

What is measured about contractions on ctg? (4)

Answer 5

• Duration (maximum 60 seconds). (>5 mins in any 10 min cycle)
• frequency (maximum ⑤ aka tachysystole 6 or more per 10 minutes )
• form (should return to baseline, not be coupled )
• relationship to FHR

Not strength!

Question 6

How report contractions on ctg that last > 5 minutes in any 10 minute cycle? Complication?

Answer 6

Excessive uterine action

Cause foetal hypoxia

Question 7

Approach to interpret ctg?

Answer 7

Dr C bravado

Dr: details; determine risk factors.
C: contractions
Bra: baseline rate
V: variability
A: accelerations
D: Decelerations
O: overall impression

Question 8

Label picture 23

Answer 8

Left: early deceleration
Middle: late
Right: variable

Question 9

Most common cause early deceleration?

Answer 9

Head compression

Question 10

Most common cause late deceleration?

Answer 10

Uteroplacental insufficiency

Question 11

Most common cause variable deceleration?

Answer 11

Umbilical cord compression

Question 12

Name 3 indications for 6 hourly antenatal ctg

Answer 12

• Iugr with absent end diastolic flow
• pre-eclampsia
• APH of unknown origin

Question 13

Name indications for twice daily antenatal ctg

Answer 13

• pprom

All other admitted patients should get daily ctg

Question 14

Management non-reassuring ctg? (4)

Answer 14

• examine and run continuous ctg
• if contraction abnormalities: stop oxytocin or give salbutamol (dilute 500 ug in 100 ml nacI ie 5 ug ml and give 2 ml iv over 2 min)
• fluid bolus
• change maternal position

Question 15

Management pathological ctg? (3)

Answer 15

• Examine for cause, document time of diagnosis to delivery
• fully dilated → assisted delivery
• not fully dilated → intra-uterine resuscitation, c/s