Epidural Analgesia for Labour

• Maternal request for analgesia
• Early epidural recommended in a host of patient groups for adequate peripartum analgesia and anaesthesia, including but not limited to:
• Maternal obesity
• Maternal cardiac disease
• Multiple (twin) pregnancy
• Pre-eclampsia
• Previous caesarean section
• Breech presentation

• Higher patient satisfaction
• Increased safety vs. GA if top-up used
• Improved post-operative analgesia

• A Scottish population study of over 560,000 labouring women (BMJ, 2024) found labour epidural analgesia was associated with:
• An overall 35% reduction in severe maternal morbidity
• A 50% reduction in women with a medical indication for epidural (e.g. cardiorespiratory disease, pre-eclampsia, BMI ≥40, multiple pregnancy)
• A 47% reduction in women delivering preterm; the effect grew as gestational age fell
• Only around 1 in 4 women with a medical indication actually received an epidural


• The likely mechanism is the bundle of care that comes with an epidural rather than the drug itself:
• Closer monitoring and established IV access
• Blunting of the physiological stress response to labour
• Avoidance of GA for operative delivery
• Faster escalation to definitive obstetric intervention

• The data for this section largely comes from NAP3
• Fortunately for the parturient, obstetric epidurals have a lower incidence of complications than epidurals inserted in other settings

• Failure rate may be as high as 33% in obese patients
• Re-site rate increases linearly with BMI


• The dose required for an epidural to work is dependent on several factors
• Approximately 1 to 2ml of LA is required per segment to be blocked


• The incidence of inadequate analgesia can be reduced by:
• LOR to saline rather than air reduces patchy block
• Senior anaesthetist inserting


• Troubleshooting:
• Ensure appropriate connections and functioning of equipment
• Low block may necessitate further boluses of LA ± increased infusion rate
• Unilateral block may require altered positioning ± withdrawal of catheter 1cm
• Patchy block may require boluses of LA / fentanyl

• Higher prevalence in obese patients: 4 in 100
• Incidence reduced by:
• LOR to saline rather than air
• Ultrasound guidance
• Senior anaesthetist
• See separate page on PDPH

• Intrathecal injection produces a rapidly ascending block with characteristics of a spinal anaesthetic
• See separate page on managing high neuraxial block

• Temporary nerve damage: 1 in 1,000
• Permanent nerve damage: 1 in 15,000

• Itching (10%)
• Nausea and vomiting
• Shivering
• Urinary retention and need for urinary catheter
• Delayed respiratory depression

• A common occurrence
• If block level is above T4, reduce the rate of infusion
• Look for and treat other causes of hypotension

• Affects around 1 in 5 women with a labour epidural
• See the epidural-related maternal fever section below

• Epidural analgesia does not increase the risk of culture-positive infection in mother or neonate
• Epidural abscess: 2 in 100,000
• Meningitis: 1.5 in 10,000
• Most common organism is Staph. aureus

• Do not increase risk of LSCS
• Do not increase duration of the 1^st stage of labour


• Prolonged 2^nd stage
• Increased need for assisted delivery

• There is no convincing evidence that neuraxial labour analgesia increases the risk of autism spectrum disorder, ADHD or other neurodevelopmental disorders (BJA, 2026)
• The small associations seen in population studies disappear in sibling-matched analyses, pointing to residual confounding rather than a causal effect
• Women should not be dissuaded from epidural analgesia on neurodevelopmental grounds

• Bruising is common
• Epidural haematoma is rare: 1 in 168,000
• However, if no improvement in motor block 4hrs post-cessation of epidural need to request urgent MRI
• Ensure appropriate timing with respect to anti-platelet and anti-coagulant medication

• Eepidural hyperthermia is arguably a more accurate name for this phenomenon, as an inflammatory cause is unproven
• Intrapartum hyperthermia is defined as a core temperature of:
• ≥38°C on one occasion, or
• ≥37.5°C on two consecutive occasions 2hrs apart
• Incidence: around 20% (15 to 25%) of women with an epidural vs. 5% without
• Unique to labour; temperature rises steadily after insertion (approx. 0.15°C/hr), so longer labours carry greater risk
• It cannot be clinically distinguished from intrapartum infection

• Neither is proven, and they are not mutually exclusive

• Maternal and neonatal sepsis screens and antibiotic treatment
• Twofold association with operative delivery; possibly coincidental as both are linked to long labours
• Intrapartum hyperthermia of any cause is associated with neonatal brain injury (BJA, 2021)
• However, there is no strong evidence that epidural-related fever specifically causes neonatal harm (no association between epidural analgesia and HIE in a large cohort study)

• Manage as for intrapartum infection, regardless of epidural status:
• Blood cultures and look for a source
• Paracetamol
• IV broad-spectrum antibiotics
• Neonatal sepsis evaluation ± IV antibiotics (benzylpenicillin and gentamicin)
• Early delivery only if evidence of fetal compromise


• No effective preventative treatment exists:
• Prophylactic antibiotics: ineffective
• Prophylactic paracetamol: ineffective
• High-dose methylprednisolone: reduces fever but increases neonatal bacteraemia
• Lower dose epidural regimens: no convincing benefit

• The OAA lists fever as an adverse effect of labour epidurals
• It is reasonable to inform women of the risk of sepsis evaluation and antibiotic treatment
• Links with operative delivery and neonatal brain injury are unproven; be prepared to discuss them if asked, but avoid dissuading women (particularly high-risk women) from an epidural

• Epidural opioids cross the dura, binding to opioid receptors in:
• The spinal cord white matter
• Substantia gelatinosa of the dorsal horns
• They also spread cephalad and act on the brainstem
• They're systemically absorbed via epidural veins and thus act systemically too

• Fentanyl is the opioid of choice owing to:
• Rapid onset of action
• Short duration of action
• Reduced cephalad spread, reducing the risk of respiratory depression

• The Bromage score is a simple, eponymously named score from 1965
• Modifications to the score (e.g. by Breen in 1993) add more categories, which I've never found particularly useful