The National Institute for Health and Care Excellence (NICE) has issued a post-publication amendment to its guideline on fetal monitoring in labour. The update clarifies how decelerations in fetal heart rate should be categorised and updates the definition of late decelerations, helping healthcare professionals identify fetal hypoxia more effectively.
Key changes to deceleration assessment
The amendment affects recommendation 1.4.24, which categorises decelerations on cardiotocography (CTG) traces into white, amber, and red categories:
- Amber category: Late decelerations have been removed from amber.
- Red category: Late decelerations are now considered a red feature regardless of duration or repetitiveness, reflecting their association with fetal hypoxia.
- Definition of late decelerations: The updated definition removes the reference to decelerations being “repetitive and periodic” to better align with current evidence.
Decelerations are defined as transient episodes when the fetal heart rate slows by more than 15 beats per minute for 15 seconds or more. Variable decelerations in traces with reduced variability may be shallower. Clinicians are advised to consider timing, duration, recovery to baseline, repetitiveness, shouldering, and variability when assessing the significance of decelerations.
Why this matters
Monitoring the wellbeing of the baby during labour is vital in all birth settings, including at home, midwifery-led units, and obstetric units. The guideline covers:
- Risk assessment to determine the most appropriate monitoring method
- Interpreting CTG traces and acting on concerning features
- Escalation if fetal hypoxia is suspected
Longer and later decelerations, especially with rises in baseline heart rate or changes in variability, increase the risk of fetal compromise. Variable decelerations without concerning features are common and often benign, typically associated with cord compression. Early decelerations are rare, generally benign, and usually linked to head compression.
The guidance applies to healthy women in labour at term. Of the 625,000 live births in England and Wales in 2021, about 90% were single babies born at term, meaning these recommendations affect over half a million women annually.
The IPS encourages members and maternity teams to review these updates to ensure clinical practice aligns with the latest NICE guidance.
Full details of the guideline and amendment are available on the NICE website.
