Excerpt from the NICE Guideline
CTG Has 3 features- Baseline rate, Variability, Decelerations on the basis of which CTG Can be categorized as Normal, Suspicious or Pathological. ( remember RNA)
The 3 features can individually be – Reassuring, Non- reassuring or Abnormal. ( Remember NSP)
Features of CTG
| ? | Reassuring | Non Reassuring | Abnormal |
| BASELINE ( bpm) | 110 TO 160 | 100 to 109 161 to 180 | Less than 100 More than 180 |
| VARIABILITY ( bpm) | 5 to 25 | Less than 5 for 30 to 50 min OR More than 25 for 15 to 25 minutes | – Less than 5 for more than 50 minutes OR – More than 25 for more than 25 minutes OR – Sinusoidal |
| DECELERATIONS | None or early. Variable decelerations with no concerning characteristics for less than 90 minutes | Variable decelerations with no concerning characteristics for 90 minutes or more OR Variable decelerations with any concerning characteristics in up to 50% of contractions for 30 minutes or more OR Variable decelerations with any concerning characteristics in over 50% of contractions for LESS than 30 minutes OR Late decelerations in over 50% of contractions for less than 30 minutes, with no maternal or fetal clinical risk factors such as vaginal bleeding or significant meconium | Variable decelerations with any concerning characteristics in over 50% of contractions for 30 minutes OR Variable decelerations with any concerning characteristics in over 50% of contractions for less than 30 min if any maternal or fetal clinical risk factors. OR Late decelerations for 30 minutes OR Late decelerations for less than 30 minutes if any maternal or fetal clinical risk factors OR Acute bradycardia, or a single prolonged deceleration lasting 3 minutes or more |
Rethink-
- Variable decelerations with no concerning characteristics are
1. Reassuring for 90 min
2. At and beyond 90 min, they become a non-reassuring feature.
- Variable decelerations with concerning characteristics-
( Think about- a. Clinical risk factor(s), b. whether the decelerations have bee present for less than or more than 50% contractions, c. Duration- Less than or more than 30 min)
1.If with less than 50 % contractions, they are Non reassuring till 30 minutes OR MORE !
2. Without maternal/fetal clinical risk factors ( The DR in DR C BRAVADO)
-If with MORE than 50 % contractions, they are non reassuring till LESS than 30 minutes. If the same continues for 30 min or more- they become an 'Abnormal' feature.
3. With maternal or fetal clinical risk factors- then they are considered ABNORMAL if present in MORE than 50 % contractions for less than 30 minutes.
- Late decelerations
1. With No maternal or fetal clinical risk factors- They are non reassuring at MORE THAN 50 % Contractions, for less than 30 min.
At 30 min or beyond, all Late decelerations ( regardless of relationship to contractions) - are ABNORMAL.
2. With maternal or fetal clinical risk factors-
- Any late deceleration is deemed ABNORMAL.
Useful lInk- https://www.frimleyhealthandcare.org.uk/media/1780/fetal-monitoring-including-fetal-blood-sampling-v21-6-may-2020.pdf
-NORMAL CTG- When ALL Features are reassuring.
– Suspicious CTG- 1 Feature Non reassuring AND other 2 are Reassuring
– Pathological CTG- when there are – 1 ABNORMAL OR 2 NON REASSURING FEATURES.
If CTG is suspicious- Check for any underlying cause- Hypotension( is the patient supine? did she receive epidural bolus recently?) , Hypertsimulation( reduce oxytocin drip) . Call senior. Perform a set of observations on the mother- PR, BP, Check contractions, vaginal exam if needed.
If CTG is pathological– Obtain a review by an obstetrician and a senior midwife. Exclude acute events (for example, cord prolapse, suspected placental abruption or suspected uterine rupture) . Correct any underlying causes, such as hypotension or uterine hyperstimulation . Start 1 or more conservative measures ( Change maternal position, iv hydration, reduce/stop oxytocin infusion) .
If the cardiotocograph trace is still pathological after implementing conservative measures: Offer digital fetal scalp stimulation and document the outcome. If the cardiotocograph trace is still pathological after fetal scalp stimulation-
– consider fetal blood sampling
– consider expediting the birth
-take the woman’s preferences into account
Fetal blood sampling
| pH | Lactate | Management |
| >= 7.25 | Less than 4.1 | Normal. If there was acceleration on scalp stimulation- consider taking a second fetal blood sample no more than 1 hour later if this is still indicated by the cardiotocograph trace. |
| 7.21 to 7.24 | 4.2 to 4.8 | Borderline – consider taking a second fetal blood sample no more than 30 minutes later if this is still indicated by the cardiotocograph. ( So if CTG becomes normal- Don’t repeat Sampling). |
| 7.20 or below | 4. 9 or more | Abnormal- Expedite birth |
If fetal blood sample cannot be obtained-
1. But there was acceleration on scalp stimulation- Review the case and decide whether to continue to observe, or to expedite delivery.
2. If sample cannot be obtained and there has been no improvement in the cardiotocograph trace, expedite the birth.
To exercise on some real CTGs, take the quiz