1. Chapter 16 CTG Dr Areefa Albahri

2. 2 FHR as a screening test Intrapartum FHR monitoring is a screening test that provides information to alert the clinician that a true test for fetal welfare assessment needs to be performed, eg: An atypical variable (pathological feature) fetal blood sampling should be performed

3. 3 FHR evaluation Dr C Bravado  ALSO DR – determine the risk C – contractions Bra – baseline rate V – variability A – accelerations D – decelerations O – overall assessment (followed by a management plan)

4. 4 FHR Monitoring on admission in labour ??? Electronic FHR monitoring ??? Doppler auscultation ??? Pinards

5. 5 Who should have continuous electronic FHR monitoring? Antenatal risk factors – Prematurity – Pre-eclampsia/eclampsia – Diabetes – Growth restriction – Non-reassuring antenatal fetal welfare assessment – Multiple pregnancy – Malpresentation

6. 6 Who should be have continuous electronic FHR monitoring? Intrapartum factors – Syntocinon – Meconium – Epidural – Suspicious FHR on auscultation – Prolonged rupture of the membranes – Prematurity – Previous C/S

7. 7 Practice Recommendations for intermittent auscultation Healthy women with uncomplicated labour IA with Pinards/Doppler recommended Active labour- after contraction for at least 60 seconds & at least every 15mins 1 st stage every 5mins 2 nd stage Continuous EFM is recommended if:  Baseline 160bpm;  Decelerations or intrapartum risk factors develop

8. 8 Categorization of FHR Features

9. 9 Baseline rate Normal = 110 – 160bpm Bradycardia (moderate) = 100 – 109bpm Bradycardia (abnormal) = < 100 bpm Tachycardia (moderate) = 161 – 180 bpm Tachycardia (abnormal) = >180 bpm (RCOG) VariabilityGreater than 5bpm and less than 25bpm Increased variability is often seen following an acute hypoxic event.

10. 10 Baseline Rate

11. 11 Baseline Bradycardia Bradycardia (moderate) = 100 – 109bpm Bradycardia (abnormal) = < 100 bpm Rare Consider the cause if this is a sudden event – ? prolonged deceleration

12. 12 Causes of Baseline Tachycardia Excessive fetal movement Maternal dehydration Prematurity Maternal fever Maternal or fetal stress causing adrenaline release Chorioamnionitis

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14. 14 Causes of Reduced Variability = 5bpm fetal sleep or quiet state Maternal medications – Morphine, Pethidine etc Fetal hypoxia – depressing the CNS Fetal anomalies Fetal Cardiac Arrhythmias

15. 15 Sinusoidal Wave like pattern of 3 – 5 oscillation / min ranging between 5 – 15 beats

16. 16 Decelerations Early Late Variable – typical and atypical Prolonged

17. 17 Early Repetitive from one contraction to another Recovery to baseline is always at the end on the contraction Caused by vagal nerve stimulation

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19. 19 Late Decelerations Repetitive from one contraction to the next (3 or more) Recovery to baseline is late, well after the end of the contraction More ominous when associated with minimal variability &  baseline Reflects a change in placental ability to adequately meet fetal needs May indicate the presence of fetal hypoxia and acidosis Often signifies fetal decompensation

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22. 22 The Fetal Heart Rate – Late decelerations Lates represent fetal hypoxia and are related to an interruption in O 2 supply at cardiac level Reduced O 2 leads to stimulation of chemoreceptors Results in activation of the cardiac centres in the brainstem SA node is effected and the FHR slows. With the prolonged hypoxia, myocardium is effected causing further decrease in the FHR and hypotension Recovery is slower as the myocardium gradually reoxygenates

23. 23 Variable Decelerations Repetitive or intermittent Rapid sudden fall in FHR Often rapid recovery Reflect some degree of umbilical cord impingement Often seen when liquor volume is 

24. 24 Shoulders Baseline Rate Typical variables

25. 25 1cm per min Baseline Rate Overshoot

26. 26 Prolonged Decelerations FHR falls for > 3 minutes Usually associated with an acute insult - Top up, VE,  Syntocinon FHR pattern before and in recovery indicates fetal tolerance - not the deceleration itself Should be managed vigorously

27. 27 Suspicious FHR Pattern: What should you do? Maternal Position Dehydration Infection Hypotension ?V.E/bedpan Vomiting/vasovagal Analgesia/Drugs Mechanical Poor quality CTG Maternal pulse Transducer site FSE Oxytocics Prostaglandins

28. Typical variable decelerations Typical variable decelerations occur in response to interment cord compression and are commonly seen during the second stage of labour. They are quick to recover to the normal baseline, have normal variability, last less than 2 minutes and have evidence of shouldering, which is a normal physiological response to intermittent cord compression.

29. Atypical variable decelerations These decelerations can be an indicator of hypoxia and have some or all of the following features: Loss of acceleration (shouldering) before and after deceleration Delayed recovery back to baseline Rebound tachycardia – caused by catecholamine release in response to stress Loss of variability/change in baseline rate.

30. 30 That is AllThanks