Foetal Asphyxia / CTG

Question 1

What is the definition of Foetal hypoxia ?

Answer 1

reduced oxygen supply to the foetus , associated with a prolonged drop in oxygen level (hypoxaemia) and an increase in carbon dioxide level (hypercapnia) in the foetal blood

Question 2

What are the causes of foetal hypoxia ?

Answer 2

1-Uterine hyperstimulation
2- Maternal disease (placental disease, placental abruption, etc.)
3-Cord compression
4-Intrinsic foetal disease
5- Maternal supine hypotension syndrome
6- Drugs administered for analgesia and anaesthesia

Question 3

What are the cases that Continuous EFM should be used in low risk pregnancies ?

Answer 3

1- oxytocin is being used for induction or augmentation of labour
2- epidural analgesia
3- vaginal bleeding in labour
4- maternal pyrexia
5- fresh meconium-stained liquor

Question 4

What are the Four main features of the fetal heart rate must be observed on the cardiotocograph?

Answer 4

1-baseline heart rate
(2) baseline variability
(3) decelerations;
(4) acceleration

Question 5

When does Reduced baseline variability commonly occur normally?

Answer 5

1- during foetal sleep cycles
2- up to 40 minutes during labour
3- drugs: opioids/ MGSO4

Question 6

What is the definition of Deceleration ?

Answer 6

A sudden decrease in FHR by more than 15 beats/min lasting for more than 15 seconds but less than 2 minutes from the baseline

Question 7

What are the types of decelerations in FHR ?

Answer 7

(1) early, (2) late, and (3) variable decelerations

Question 8

What is the clinical value of presence of decelerations ?

Answer 8

🩷 in labour: it is possible for some non-pathological type of decelerations to occur
🌸 antenatal period : should always be considered pathological.

Question 9

What is the definition of Early decelerations ?

Answer 9

*begin at about the same time as the onset of the uterine contraction.
* The nadir of early decelerations coincides with the peak of contraction
🔮 uncommon

Question 10

What is the clinical Significance of early decelerations ?

Answer 10

Normal and common
usually not indicative of foetal compromise. They may occur due to head compression during uterine contractions.

Question 11

What is the most ominous FHR pattern ?

Answer 11

Late decelerations

Question 12

What is the definition of Late decelerations ?

Answer 12

The onset of these decelerations occurs after the beginning of the contraction, and the nadir of the deceleration occurs after the peak of the contraction

Question 13

What is the meaning of Uncomplicated variable decelerations?

Answer 13

Not associated with other FHR abnormalities, e.g.,baseline changes and reduced variability
🌸not consistently associated with poor neonatal outcome

Question 14

What is the definition of Acceleration in FHR monitoring?

Answer 14

transient increases in FHR of 15 beats/min or more, which lasts for 15 seconds or more
associated with good outcome.

Question 15

What is the minimum period of time to label The foetal heart pattern as sinusoidal ?

Answer 15

if this pattern lasts for at least 10 minutes

Question 16

What are the causes for sinusoidal pattern ?

Answer 16

foetal anaemia
massive foetal haemorrhage due to causes such as maternal anticoagulation therapy (aspirin,
warfarin, etc.),
bleeding vasa praevia, cordocentesis,
Rh isoimmunisation, .
Maternal administration of some sedative and analgesic drugs like meperidine, pethidine,
butorphanol, and alphaprodine (but not other narcotics)

Question 17

How to manage Sinusoidal pattern due to pethidine ?

Answer 17

naloxone

Question 18

How to manage if sinusoidal pattern appears in labour ?

Answer 18

foetomaternal haemorrhage must be clinically excluded

Question 19

How to interpret the CTG results?

Answer 19

DR C BRAVADO
DR define risk
C contractions
BRA baseline rate
V variability
A accelerations
D decelerations
O overall impression

Question 20

According to DR C BRAVADO
What is the meaning of DR ( define risk) ?

Answer 20

Low risk or high risk pregnancy
Is there any risk factor as
Meconium stained liquor
IUGR / fever …

Question 21

How to asses contractions on CTG scan?

Answer 21

Frequency ( 4-5 ) / 10 minutes
Duration

Question 22

What is the normal range for fetal heart rate baseline?

Answer 22

110 - 160

Question 23

What to check first in case of fetal tachycardia on CTG ?

Answer 23

Maternal temperature

Question 24

What is the normal fetal heart variability?

Answer 24

5- 25 beats / minute

Question 25

Explain the ABCDE approach to predict the next change in pathological CTG ?

Answer 25

hypoxia begins with decelerations
A : Accelerations disappear
B : Baseline heart rate increases
C : Compensated stress ( stable baseline + normal variability)
D : Decompensation ( unstable baseline + changes in variability)
E : End stage ( myocardial failure + step ladder pattern to death)

Question 26

What is the most common type of decelerations on CTG scan?

Answer 26

Variable 80 - 90 %

Question 27

What is the definition of shouldering on CTG ? What does it predict?

Answer 27

increase in heart rate preceding and/or following decelerations
* the fetus isn’t hypoxic yet
🔮 commonly occurring with cord compressions.

Question 28

What are the concerning characteristics of variable decelerations?

Answer 28

1- lasting > 60 seconds
2- biphasic shape
3- no shouldering
4- reduced baseline variability within deceleration
5- failure to return to baseline

Question 29

According to NICE , how to classify the baseline rate on CTG ?

Answer 29

Reassuring: 110 - 160
Non-reassuring:* increase in baseline fetal heart rate of 20 beats a minute or more from the start of labour or since the last review an hour ago
*100 to 109 beats /mins
*unable to determine baseline
Abnormal: < 100 / > 160

Question 30

According to Nice, how to classify variability on CTG ?

Answer 30

Reassuring: 5- 25 b/ m
Non- reassuring: < 5 for 30 - 50 mins
Or > 25 for 10 mins
Abnormal : < 5 for > 50 mins
Or > 25 for > 10 mins
Or sinusoidal pattern

Question 31

How to classify decelerations according to Nice?

Answer 31

🚩Reassuring: - none or early
- variable with no concerning
characteristics for < 90 mins
🚩 non- reassuring: - variable with
no concerning characteristics for
> 90 mins
- variable with any concerning
characteristics in up to 50% of
contractions for > 30 mins
- variable with any concerning
characteristics in > 50 % of
contractions for < 30 mins
- late decelerations in > 50 % of
contractions for < 30 mins
🚩 abnormal: variable with any
concerning characteristics in > 50
% of contractions for 30 mins
- late for 30 mins
- acute bradycardia
- single prolonged deceleration
lasting > 3 mins

Question 32

When is the CTG scan called suspicious? How to manage?

Answer 32

1 feature non reassuring
2 reassuring features
🔮 1- change position
2- IV fluids
3- stop syntocinon

Question 33

What is the CTG scan called pathological? How to manage?

Answer 33

1or more abnormal feature
Or :
2 or more non reassuring features
🔮 1-consider fetal scalp stimulation
2- FBS
3- expedite delivery

Question 34

Fetal acute bradycardia, what is the rule of management?

Answer 34

3 call for help
6 move to the theater
9 prepare for delivery
12 aim to delivery

Question 35

What is The frequency of intermittent auscultation during labour?

Answer 35

preferably done after contraction, for a minimum period of 60 seconds

every 15 minutes during the first stage
every 5 minutes during the second stage

Question 36

In the pregnancies previously monitored with intermittent auscultation,when is continuous EFM recommended ?

Answer 36

1- foetal heart baseline < 110 beats/min or > 160 beats/min on auscultation
2- any decelerations
3- Development of any risk factors during labour
♥️ CTG normal for 20 mins 👉 return to intermittent auscultation

Question 37

What are the Contraindications to foetal blood sampling.
?

Answer 37

1-Maternal infection such as human immunodeficiency virus (HIV), hepatitis viruses, or herpes
2- Foetal bleeding disorders such as haemophilia
3- Prematurity (<34 weeks)
4- Acute foetal compromise

Question 38

What is the Interpretation of foetal blood sampling.
?

Answer 38

1- >7.25 Reassuring (normal)
: normal monitoring to be performed
2- 7.21–7.24
Borderline
(preacidaemia)
: Sampling to be repeated within 30 minutes
3- <7.20
Foetal acidosis
: Urgent intervention

Question 39

What is the benefit of Foetal Scalp Lactate Measurement upon FBS ?

Answer 39

it requires much less amount of blood in comparison to that required for FBS (5 µL vs. 35–50 µL)

Question 40

What are the antenatal maternal Indications for continuous CTG in labour?

Answer 40

1- previous CS or other full thickness uterine scar
2- any hypertensive disorder needing medication
3- prolonged ruptured membranes
4- any vaginal blood loss other than a show
5- suspected chorioamnionitis or maternal sepsis
6- diabetes (type 1 or type 2) and gestational diabetes requiring medication

Question 41

What are the antenatal fetal Indications for continuous CTG in labour?

Answer 41

1- non-cephalic presentation
2- FGR
3- SGA + other high-risk features such as abnormal doppler scan results, reduced liquor
volume or reduced growth velocity
4- advanced gestational age (more than 42+0)
5- anhydramnios or polyhydramnios
6- reduced fetal movements in the 24 hours before the onset of regular contractions.

Question 42

What are the intrapartum Indications for continuous CTG in labour?

Answer 42

1- contractions that last longer than 2 minutes, or 5 or more contractions in 10 minutes
2- the presence meconium
3- maternal pyrexia (a temperature of 38°C or above on a single reading or 37.5°C or above on 2 consecutive occasions 1 hour apart)
4- suspected chorioamnionitis or sepsis
5- pain reported by the woman that differs from the pain normally associated with contractions
6-fresh vaginal bleeding that develops in labour
7- blood-stained liquor
8- maternal pulse over 120 beats a minute on 2 occasions 30 minutes apart
9- severe hypertension (a single reading of either systolic of 160 mmHg or more or diastolic of 110 mmHg or more, measured between contractions)
10- hypertension (either systolic of 140 mmHg or more or diastolic of 90 mmHg or more on 2
consecutive readings taken 30 minutes apart
11- a reading of 2+ of protein on urinalysis and a single reading of either raised systolic (140 mmHg or more) or raised diastolic (90 mmHg or more)
12- confirmed delay in the first or second stage of labour
13- insertion of regional analgesia (for example, an epidural)
14- use of oxytocin.