Fetal Monitoring and CTG

Classification of intrapartum FHR trace features
Interpretation of CTGs
Definition of normal, suspicious and pathological FHR traces

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Classification of intrapartum FHR trace features (from NICE/RCOG guideline)

Feature	Baseline (bpm)	Variability (bpm)	Decelerations	Accelerations
Reassuring	110-160	≥5	None	Present
Non-reassuring	100-109 161-180	<5 for 40-90 minutes	Typical variable decelerations with over 50% of contractions, occurring for over 90 minutes Single prolonged deceleration for up to 3 minutes	The absence of accelerations with otherwise normal trace is of uncertain significance
Abnormal	<100 >180 Sinusoidal pattern ≥10 minutes	<5 for >90 minutes	Either atypical variable decelerations with over 50% of contractions or late decelerations, both for over 30 minutes Single prolonged deceleration for more than 3 minutes

 

Interpretation of CTGs

• Patient ID, time and date
• Paper speed
• Contractions
• Baseline heart rate
• Variability
• Accelerations
• Decelerations
• Categorise: normal/suspicious/pathological
• Management

Definition of normal, suspicious and pathological FHR traces (from NICE/RCOG guideline)

Category	Definition
Normal	An FHR trace in which all four features are classified as reassuring
Suspicious	An FHR trace with one feature classified as non-reassuring and the remaining features classified as reassuring
Pathological	An FHR trace with two or more features classified as non-reassuring or one or more classified as abnormal