- Design
- Multicentre prospective observational study
- Population
- 952 nulliparous women at term with epidural labour analgesia
- Primary outcome
- Intrapartum hyperthermia (≥38°C)
- Effect
- 13% hyperthermia; OR 1.64 (1.40–1.91) per point lower time-weighted pain
A multicentre prospective study followed 952 nulliparous women at term having epidural labour analgesia, recording pain scores from before the block to the end of the third stage.
Intrapartum temperature of 38°C or more occurred in 13%. Lower pain scores were associated with higher odds of hyperthermia on every measure; for the time-weighted average, each point lower raised the odds (OR 1.64, 95% CI 1.40 to 1.91). A time-weighted average score of 3 or less was associated with sharply higher odds (OR 8.67, 4.19 to 17.9).
This supports the idea that a dense, extensive sympathetic block reduces sweating and heat loss, contributing to epidural-related fever. It is observational, and other drivers such as inflammation and labour duration may also play a part.
It does not argue for leaving women in more pain. It does suggest that unusually dense blocks deserve attention, and that a febrile woman with a very effective epidural is a recognisable pattern, though infection must still be considered.
- Monitor temperature regularly in women with an epidural in labour.
- Note when the block is unusually dense or extensive.
- Consider titrating to effective rather than maximal analgesia.
- Do not assume fever is epidural-related without assessing for infection.
Why it matters
It points to block density as a modifiable contributor to epidural-related fever.
Don't overread it
Observational; it shows association with low pain scores, not that lighter blocks prevent fever.
The statistics, in plain English
An odds ratio of 1.64 per point means each one-point drop in average pain was linked to about 64% higher odds of fever. The wide interval for the threshold estimate (4.2 to 17.9) shows its size is uncertain even though the direction is clear.
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