What is Epidural Related Maternal Fever?

Epidural Related Maternal Fever (ERMF) is a very common complication of epidurals for labor pains.  

Between one in ten to one in five (10-20%) of women in labor who use epidurals for their labor pains start running fevers from their epidurals.

This fever is not from an infection.  ERMF is an immune response -- like an allergy – that the mother makes against her labor epidural.

There are two risks.

One is very common.

The other is very rare.

The common risk is that mothers who get ERMF often are treated with powerful antibiotics that they don’t really need - both before and after they deliver. The same is true of their newborns.

In particular, too many babies get exposed to too many antibiotics.

Antibiotic treatment upsets the normal way that newborns acquire the healthy bacteria that all of us need in our bowels. Bad bowel bacteria can cause lots of problems later on in childhood.

The rare risk is brain damage from high fevers that go on for a long time before delivery.  

The fetal brain consumes the majority of the unborn baby’s energy.  And Mom’s fever makes the fetus need more energy – 15% more for every extra degree.   

Very rarely, when a woman in labor runs a high fever for a long time - the fetus’ brain malfunctions.

Newborns can have strokes, or seizures, or other long-lasting brain issues - including cerebral palsy.

No. Most women in the United States – most women worldwide who live in resource-rich countries – get an epidural to help with their labor pains for a very good reason.

Epidurals tend to control labor pain better than the alternatives.

And, other than sometimes giving mom fevers, labor epidurals are very safe.

Think about it this way. ERMF happens in 10-20% of labors – not most - so the odds are in your favor.

The longer her labor epidural is in, the more likely mom will react to it and run a fever . So, first time moms – who tend to have longer labors – are at highest risk.

Anesthesiologists need to stop ignoring the medical evidence.

Before epidurals 1-2 % of women ran fevers during labor. Now it’s 10-20% - and all those 'extra’ fevers happen among women who get epidurals.

So, my recommendation is that Anesthesia stop putting all the responsibility for managing fever during labor onto the Obstetrician.

In the real world, the only things an Obstetrician can do is decide whether or not to give antibiotics or acetaminophen (Tylenol) to a woman in labor who is running a fever.

And Tylenol doesn’t work very well for ERMF

Meanwhile, fully 90% of fevers during labor are ERMF. Not an infection. Not something antibiotics - or Tylenol - can treat.

Mom - ERMF is too important to be managed in such an ineffective way.!

Close monitoring of patient temperature is routine down in the Operating room for all patients getting surgery.

Patients getting spinal epidurals are monitored particularly closely. Simple thermometers are attached to the patient - and no patient is allowed to get too hot - or too cold. Women in labor, carrying unborn babies, deserve at least the same attention.

Most laboring women do tolerate fevers well – but there’s also an unborn child to protect.

Maternal fever over 38 C – 100.4F – stresses the fetus.

Anesthesiologists should try not to let it happen. And treat it, when it does.

It’s true that many obstetricians - and mothers-to-be - think turning the delivery room temperature way down or using a cooling blanket or a cool mist fan to bring down Mom’s temperature would be awkward or uncomfortable during labor.

But anesthesiologists are smart people. I’m sure that they could figure out some way to control the temperature of a woman who is running a high fever during labor without getting too much in Mom’s - or the obstetrician’s - way.

A lot. Doctors do know that ERMF is not an infection that can be treated by antibiotics. But doctors don’t know if it’s the catheter or the anesthetic drugs – or both - that triggers mom’s immune response.

Doctors also don’t know how best to predict or prevent ERMF – or how best to distinguish ERMF from the real infections that still cause some women to run fevers during labor.

Epidural analgesia for labor is a multi-billion dollar a year industry - especially in the United States.

And I believe that the doctors, hospitals, medical device manufacturers, and pharmaceutical companies who profit from that industry are afraid that might change - should too many women learn too much about ERMF.

The catheter manufacturers and pharmaceutical companies are afraid of losing market share – and getting sued for product liability.

Doctors and hospitals are petrified by fear of medical malpractice suits - justified or not.

No one dares to talk about ERMF- or pay for the research needed to fix it.

There is only one alternative for pain control during labor that is well-studied, widely used, and safe for both mother and baby.

Inhaling a 50-50% mixture of medical grade oxygen and nitrous oxide – oxygen and ‘laughing gas’.

Doctors and midwives have used nitrous oxide to help women with their labor pains for over 100 years.

Mom takes a few deep breaths of it before each contraction.

And because 50% oxygen is more than twice the amount of oxygen in room air - or the bottom of a whipped cream can - medical grade nitrous/oxygen, administered under the supervision of an anesthesiologist, is very safe for both Mom and baby.

Studies do show that, on average, breathing nitrous oxide/oxygen is not quite as effective for pain control as a labor epidural - but it certainly helps.

Indeed, nitrous oxide/oxygen is the first approach to pain control during labor on most Labor and Delivery services in the UK.

In such hospitals labor epidurals remain an option - and many women get them.

Often later in labor than in the United States. When labor pains are at their worst. And childbirth is close.

So the epidural doesn’t have to stay in as long.

In the United States, however, the routine use of nitrous oxide/oxygen during labor vanished during the 1990’s.

Right around the time the epidural was anointed “the gold standard” for pain control during labor.

Obstetricians need to research antibiotic use – and overuse - among women with ERMF.

The true rate of maternal infection during labor is 1-2% But many more women and fetuses than that are exposed to powerful, broad-spectrum antibiotics because of ERMF.

Now please understand, your OB always will `err on the side of caution’ and treat more mothers in labor who run fevers with antibiotics than there are moms who actually have infections.

But back in 2011 pediatricians at Kaiser-Permanente analyzed hundreds of thousands of births. They developed a computerized risk-factor tool - an algorithm – basically a widget - for newborn infection that safely and dramatically reduced newborn antibiotic overuse.

A similar tool should be developed, now! to evaluate maternal infection risk and reduce antibiotic overtreatment of both the mother and her fetus.

One good statistician, a big Health Network’s database, and a bit of AI could develop such a tool in a matter of weeks.

After that: more research.

Consenting pregnant women who plan on having a labor epidural into a clinical trial to test just how well the new, maternal antibiotic-use tool works.

The newborn tool has worked well for over a decade.

Because I want to push my colleagues in Obstetrical Anesthesia to get right with ERMF – NOW - and so prevent a few hundred newborns every year in the United States from suffering brain damage.

I’d also like to see my friends, the Obstetricians, treat several hundred thousand fewer laboring mothers and their fetuses in the United States each year with antibiotics that they don’t really need.

Those antibiotics are not good for those moms – and can harm their newborns.

Yes. Almost all anesthesiologists are hospital based. Until recently they didn’t have a good option other than waiting until their patients actually were in the hospital before getting consent for labor epidurals

That’s far from ideal. Informed consent for any medical procedure should allow the patient time.

Time to think calmly about the risks and benefits of that procedure.

Time when the patient is not stressed.

In fact, valid informed consent for a procedure designed to relieve pain – by legal doctrine going all the way back to Nazi Germany and the Nuremberg Code – is impossible to obtain once a patient already is in pain.

Who’s going to say “No!”?

Meanwhile, it’s 2025 – not 1947.

OB Anesthesiologists should level up their standard of care and use videoconferencing to obtain valid informed consent for labor epidurals. Preferably coordinated with routine second trimester prenatal care.

They shouldn’t obtain invalid consent when Mom already is in pain and has no time to think.

AND WHEN THEY DO GET INFORMED CONSENT, ANESTHESIOLOGISTS SHOULD DISCUSS ERMF:

EPIDURAL RELATED MATERNAL FEVER.

1. Labor epidural analgesia and maternal fever.

2. Intrapartum Temperature Elevation, Epidural Use, and Adverse Outcome in Term Infants

3. Role of Perinatal Inflammation in Neonatal Arterial Ischemic Stroke

4. Fever in labour and neonatal encephalopathy: a prospective cohort study

5. Epidural analgesia, intrapartum hyperthermia, and neonatal brain injury: a systematic review and meta-analysis