When you’re pregnant, it can be hard to tell whether you’re running a fever or just running a little hot. Like most expectant moms, you may be feeling flushed or extra toasty, and you might even experience the occasional hot flash, thanks to hormonal swings and your baby-to-be radiating heat as she grows.

Here’s what you need to know about fevers during pregnancy — including what’s considered a fever in expectant women, what medicine you can take and the importance of checking in with your doctor to minimize any potential risks that a fever might pose to you and your growing baby.

What can cause a fever during pregnancy?

You can develop a fever during pregnancy for many of the same reasons you would when you’re not expecting. Some possible causes of a fever during pregnancy may include:^[2]

• The common cold. In fact, you’re probably more likely to suffer from common viral infections like colds while you’re pregnant. That’s because your immune system undergoes changes during pregnancy in order to protect your fetus, which your body considers an outsider, from being rejected. The result can be more colds, which is not so good news for your sinuses.
• The flu. As with colds, immune system changes during pregnancy can increase your risk of catching the flu (one reason why it’s so important for expectant moms to get a flu shot). Low-grade fevers may be the result of a benign viral infection like a cold, while higher fevers may be a symptom of the flu. Flu symptoms can include body aches and chills in addition to a fever.^[3]
• Bacterial infections. Sometimes, a fever can be caused by a bacterial infection — like a urinary tract infection, kidney infection or strep throat, for example — that may require antibiotics.^[4]
• Listeriosis. Although the odds of being infected with listeriosis are very low, you’re at greater risk during pregnancy. Pregnant women should avoid eating raw meat, fish and unpasteurized cheese to avoid exposure to listeria bacteria during pregnancy, which can also cause a high fever.^[5]
• COVID-19. Fever can also be a symptom of COVID-19, the illness caused by the novel coronavirus. If you think you may have been exposed to COVID-19, call your doctor immediately, as pregnant women are at increased risk for complications from the disease.^[6]

How long can a fever last when you’re pregnant?

Fever in pregnancy can last as long as the underlying cause, such as the flu, but you should call your practitioner right away if it reaches 101 degrees F. And take steps to bring down your temperature the same day it climbs to 100 degrees F or higher.

What can I take for a fever while pregnant?

While you’re waiting to speak to your doctor, take acetaminophen (Tylenol) to reduce your fever. Avoid aspirin or ibuprofen (Advil or Motrin) when you’re pregnant unless they’re specifically recommended by your practitioner.

A few more tips to treat fever during pregnancy:

• Take a tepid bath or shower
• Drink plenty of water and other cold beverages to cool down and prevent dehydration
• Keep clothing and covers light

What can I do to prevent fever during pregnancy?

Avoid catching a cold or flu by washing your hands often, avoiding sick people and getting a flu shot. Catching the flu can not only induce fever, it can potentially lead to other complications — all the more reason to get the flu vaccine at the start of flu season, ideally in October, if you’re pregnant or planning to get pregnant.

Is it risky to get a fever in early pregnancy?

You can get a fever at any time during pregnancy. Research suggests that about one-third of pregnant women will get a fever at some point, and the majority deliver healthy babies.

But while it’s possible to get a fever any time throughout your pregnancy, a high fever in the first weeks of pregnancy may be more risky than a flu later on. A study published in the journal Pediatrics associated fever, especially in the first trimester, with various birth defects — although experts caution that the fever’s source, severity, frequency and any treatment are all factors to consider when evaluating any risk.^[7]

Still, it’s a good idea to have a trusty thermometer on hand — along with your practitioner’s number — to keep a very close eye on your temperature if you’re feeling under the weather.

What effects can a fever have on pregnancy?

It’s unlikely that a fever will have an effect on your pregnancy. A mild fever under 100 degrees F is generally no cause for concern and typically won’t have any impact on your growing baby.

But a higher fever can be more serious, which is why it’s so important to give your practitioner a call and bring your temp down with acetaminophen as soon as you start to see those numbers go up.

While pregnant people and their babies are more likely to suffer from complications from an untreated high-grade fever, it’s important to know that the fever itself may not be the cause; it could be an indication of an underlying condition, such as an infection or something else.

You may also have read about studies linking multiple untreated high fevers in pregnant women with an an increased risk of autism in babies. Don’t worry too much, however, as the chances you’ll be in that situation are slim and a lot more research still needs to be done before any definitive conclusions can be drawn.

Bottom line: Prevention and swift treatment are your best defense against fevers during pregnancy — and any concerns you may have.

EXCLUSIVE REPORT – For expectant mothers nearing the finish line of pregnancy, any sudden health complication can be a source of immediate alarm. When a high fever strikes at 36 weeks—a critical “late preterm” stage—questions over safety, medication, and the risk of early labor move to the forefront.

While the primary treatment for fever in pregnancy remains the safest over-the-counter option, a confluence of accompanying symptoms like diarrhea and heavy sweating mandates an urgent call to a healthcare provider.

The Medication Question: What Obstetricians Advise

The consensus among major medical bodies, including the American College of Obstetricians and Gynecologists (ACOG), holds that Acetaminophen (Paracetamol/Tylenol) is the recommended first-line drug for treating fever during pregnancy.

The Rationale:

• Minimizing Risk to the Fetus: High and sustained maternal fever (especially above $101^\circ\text{F}$ or $38.3^\circ\text{C}$) has been linked to increased risks, including preterm birth, particularly in the later stages of pregnancy. Doctors prioritize lowering the fever to mitigate these risks.
• Safety Profile: Unlike Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) such as Ibuprofen and Aspirin, which are generally contraindicated in the third trimester due to risks like premature closure of a fetal heart duct, Acetaminophen is considered the safest option when taken at the lowest effective dose for the shortest duration.

Crucial Caveat: Pregnant women should never self-medicate with dosages exceeding manufacturer recommendations or their doctor’s advice. Consulting a physician is non-negotiable before initiating any drug regimen, even an over-the-counter one.

Beyond the Thermometer: Warning Signs That Demand Immediate Attention

While a simple viral fever often responds well to home care, the presence of accompanying severe symptoms, as reported by expectant mothers, can signal a more serious underlying issue.

A combination of High Fever, Diarrhea, and Profuse Sweating at 36 weeks is a clinical red flag, requiring immediate evaluation to rule out: