A suspicious CTG is one in which one non-reassuring feature is present:
- Baseline HR 100 – 109bpm or 161 – 180bpm
- Variability <5bpm over 40 – 90 mins
- Single prolonged deceleration ≤3 mins
- Typical variable decelerations in >50% of contractions over a 90 min period
- Absence of accelerations (doubtful significance in isolation)
Reference: NICE intrapartum care – National Institute for Health and Care Excellence (2005). Intrapartum care. CG55. London: NICE.