Epidural Fever

Epidural Fever

On one postnatal ward in a fairly average hospital at the beginning of the year in which I first wrote about this topic, almost a third of the women were being given antibiotics.

Several of these women’s babies were also receiving antibiotics.

In all of these cases, the antibiotics were being given prophylactically (or ‘just in case’) in response to symptoms of pyrexia (high temperature) and/or tachycardia (high pulse) following labour and birth while clinical staff awaited the results of swab tests.

Yet by the time the swab cultures came back, all of the women’s and babies’ symptoms had resolved. And not one of the swab tests showed any indication that they had ever had an infection.

What’s going on?

This could be the bones of a plot line for a Robin Cook novel. What caused these women and babies to show symptoms of infection, where no infection could later be found?

Were we seeing the emergence of a new and insidious wonder bug that causes people’s temperature and pulse to become raised without any signs of infection appearing on lab slides?

The truth of this scenario is less of a mystery than it might sound if one considers one other piece of information.

All of the women on this postnatal ward who were being given prophylactic antibiotics, or whose babies were having these, had an epidural during labour.

It seemed that the answer to this little mystery might be found in epidemiology rather than science fiction.

A bit of background

When I went away to research this, I discovered medical literature explaining that epidurals can raise someone’s temperature and pulse.

Unfortunately, this is rather problematic.

That’s because having a raised temperature and pulse is a sign of infection, and infection in childbearing women and babies is not something to take lightly.

So lots of women and babies end up with unnecessary testing (known in some areas as a septic work-up) and/or antibiotics as a result of having epidurals.

It’s not even as simple as saying, ‘but if more midwives and doctors knew this, they could just stop overtreating’.

Why we can’t ignore

Midwives and doctors can’t dismiss a raised temperature in a woman or baby who have been exposed to epidural analgesia just because it’s a known side effect. That’s because there’s a chance that some of the women and babies who have a raised temperature and pulse might actually have an infection.

So they need to at least document and discuss this, and potentially offer some sort of investigation to women and families. (More on the responsibilities of practitioners and how you can make your own decisions here.)

But, as I wrote in my first article on this topic:

“…surely we need to find some way of ensuring that women who have epidurals are not automatically signing themselves and their babies up for antibiotics, longer hospital stays and the potential impact these things may have on their first days together.”

A bit of history

Since 1989, if not before, we have known that epidural analgesia increases maternal and neonatal temperature and pulse, and that this should be noted as a potential side effect for women who have used this in labour.

In one early study, where a group of women who had epidural were compared to women having pethidine, the mean temperature of the women having an epidural had risen within six hours of its administration. This rise was not related to any clinical evidence of infection.

The women and babies who experienced epidural-induced pyrexia were also more likely to experience tachycardia, which means that their pulse (and thus heartbeat) speeds up as well.

Why is epidural fever a problem?

As above, epidural-related fever can lead to unwanted consequences for women and babies, including unnecessary antibiotics and interventions, such as sepsis work-ups.

Now, if antibiotics were completely safe, and no knock-on effects ensued from the practice of treating a fever, guidelines suggesting prophylactic treatment of signs of infection might not be so problematic.

Unfortunately, some of the other aspects of this scenario cause wider problems to the affected women and families. 

Women are being prevented from going home when they would like to because their babies are receiving intravenous antibiotics.

Others suffered from the effect that antibiotics can have on the immune systems of women and babies, including thrush. And that can affect breastfeeding, sleep, and other aspects of health.

Getting better statistics

When I originally wrote about this issue, the best data came from a study which showed that nearly a third of babies whose mothers had epidurals became pyrexic during labour itself, with five percent of babies reaching a temperature of over 40°c.

That 40°c threshold is important. It’s the point at which the authors felt neurological injury could be sustained.

Since then, researchers have been able to be more specific, showing that epidural-related fever affects 15-25% of women who have an epidural.

Research carried out by paediatricians over the years has highlighted the problems with the over prescription of antibiotics to neonates whose mothers have had epidurals. Agakidis et al (2011) found that babies born to women who had epidurals were five times more likely to have a sepsis work-up than babies born to women who did not have epidurals.

They found that “…epidural analgesia in labor is an independent risk factor for pyrexia in term neonates. It is unnecessary to investigate febrile offspring of mothers who have had epidurals unless pyrexia persists for longer than 5h or other signs or risk factors for neonatal sepsis are present.”

Heesen et al (2012) published one of the first reviews of this area, concluding that:

“Our data suggest that EDA-related maternal hyperthermia results in an increased likelihood of sepsis workup and antibiotic treatment of the infant. A crucial question is whether EDA-related maternal hyperthermia is truly infectious. If not, administration of antibiotics would not be justified and may be dangerous.”

This has continued to be a concern for clinicians, researchers and guideline writers.

Towards a better understanding

This phenomenon acquired an acronym, LEAF, which stands for labour epidural associated fever, and the focus on this issue is now wider.

More recent research has helped us understand what causes this phenomenon. Newer evidence suggests the fever is often not a bacterial infection, but an immune response involving signalling pathways and physiological changes induced by the epidural itself.

And current research, including pilot studies examining inflammatory markers, continues to explore this reaction, highlighting that fever is not a simple infectious process in the context of epidural analgesia.

Importantly, large cohort research has shown that while epidural analgesia is associated with higher maternal temperatures during labour, it does not appear to increase the risk of serious neonatal complications, such as hypoxic-ischemic encephalopathy, after appropriate statistical adjustment for other factors.

Individual decision making

Many health professionals are aware of the need to support parents to make the decisions that are right for them and their babies, on an individual basis.

But there will likely always be those who like to err on the side of caution and risk, and who are more comfortable with the idea of acting on a particular symptom in a prescribed way.

Some people would argue that a small proportion of these women and babies may actually have infections for which they should be offered antibiotics, and they are correct. It would be no more helpful to suggest never offering antibiotics to women and babies with signs of infection than the current situation is some areas where women and babies with signs of infection where this might be caused by epidural are always offered antibiotics.

But there are ways of taking individual factors into account here.

An important consideration

It is well understood that infection, particularly in babies, can be potentially dangerous. But the newer research, that I have mentioned above, should be reassuring on this matter.

But for those needing more reassurance… In my own practice, I have rarely seen a baby with an infection whose only symptom was pyrexia, or a high temperature. Generally they tend to show one or more other symptoms, such as breathing anomalies, being unresponsive, floppy, or jittery, not feeding well, or seeming generally unsettled. 

In fact, one older text on neonatal care (The Sick Newborn Baby, by Kelnar et al 1995) suggested that fever should not be considered essential for the diagnosis of neonatal infection. Its authors argued that the first signs of infection tend to be non-specific and behavioural, and that waiting for any concern to be confirmed by a raise in temperature can lead to a delay in treating the infection.

Similarly, it is relatively simple to explore other signs of infection with women, by looking at what happened during their birth, the condition of the placenta, and whether they are experiencing any discomfort or other symptoms. If nothing else is awry, then any fever may well be epidural-related.

The bottom line

However we do it, we need ways of ensuring that women who have epidurals are not automatically signing themselves and their babies up for antibiotics, longer hospital stays, and the potential impact these things may have on their first days together.

Because the vast majority of women and babies who have a high temperature or pulse following an epidural won’t have an infection at all.

They will simply be having an immune/inflammatory response to the effects of the epidural.

If you would like more information on how to make the decisions that are right for you, you might find this book useful:

What’s Right For Me?

An earlier version of this article was originally published as Wickham S (2002).  Epidural Fever. TPM 5(8):21.

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