A fever while pregnant can occur due to infections, such as the flu, a cold, pneumonia, COVID-19, dengue fever or urinary tract infection. It can also be a sign of an ectopic pregnancy. A fever during pregnancy may be accompanied by additional, symptoms such as painful urination, shortness of breath, body aches or a headache.

If you experience a fever while pregnant, above 37.8ºC (or 100ºF), you should first try to cool down with natural methods, like placing a a cold, wet cloth on the head, back of the neck, and armpits. You should also wear light clothing and consume hot foods that promote sweating to lower body temperature, like teas and soups.

However, you should consult your OBGYN if a fever develops during pregnancy, or is accompanied by other symptoms, so that the underlying cause can be identified, and the most appropriate treatment can be initiated.

What causes a fever during pregnancy?

The main causes of fever while pregnant are:

1. Cold and flu

The cold and flu are viral infections that can cause fever during pregnancy, as well as nasal congestion, a runny nose or body aches.

During pregnancy, a woman's immune system undergoes changes that can weaken it. Therefore, pregnant women are at a greater risk for infections, like the cold and flu.

What to do: Be sure to drink plenty of fluids and to rest whenever possible. Furthermore, it is important to consult an obstetrician to assess whether the fever is caused by the flu or cold or whether there is another type of infection present so that the most appropriate treatment can be initiated.

2. UTI

Urinary tract infections are typically caused by bacteria from the intestine, especially Escherichia coli, which reach the urinary system, due to the proximity between the urethra and the anus. It is common for women to have at least one UTI during pregnancy.

A urinary tract infection can lead to fever and other symptoms, such as pain or burning when urinating, a feeling of heaviness in the bladder, frequent urge to urinate or very dark, cloudy and strong-smelling urine. Learn about other UTI symptoms that can appear, and complete our online symptom quiz if you suspect you may have a UTI.

What to do: You should be treated with antibiotics as prescribed by your obstetrician. It is also important to drink plenty of water, to not hold your pee and to empty your bladder completely each time you urinate.

3. Dengue or Zika

Dengue and Zika are infections caused by viruses transmitted through the bite of Aedes aegypt mosquito. These infections can cause symptoms such as fever above 38ºC, red spots on the skin, pain and swelling in the joints.

Dengue fever during pregnancy is dangerous as it can interfere with blood clotting. This can cause the placenta to detach and lead to a miscarriage or premature birth. Read more about the symptoms of dengue and how to identify it.

With Zika, the virus can pass to the baby through the placenta and cause complications like microcephaly.

What to do: Treatment of dengue and Zika during pregnancy includes rest, hydration, and the use of analgesics as prescribed by the obstetrician to combat pain and fever. Dengue treatment may require hospitalization for IV fluids and medications to reduce the risk for complications like miscarriage or bleeding.

4. Gastroenteritis

Gastroenteritis, or food poisoning, is an infection of the digestive system that can occur after consuming food contaminated with bacteria or viruses. It can cause symptoms such as diarrhea, abdominal pain, vomiting and fever.

What to do: You should rest and drink plenty of fluids as gastroenteritis can lead to dehydration. Be sure to consult your obstetrician to identify the cause of gastroenteritis. Cases that are caused by a bacterial infection may require antibiotics for treatment.

5. Sore throat

Inflammation in the throat can be caused by viruses and bacteria, and lead to symptoms such as a sore throat, difficulty swallowing and fever.

Tonsillitis caused by bacteria can cause visible white spots on the throat and tonsils.

What to do: You should consult your obstetrician to assess the underlying cause of the sore throat. Bacterial infections, for example, may require treatment with antibiotics. To relieve a sore throat, you can gargle with warm salt water or drink ginger and lemon tea to complement the treatment recommended by your doctor. Check-out other ways to relieve a sore throat while pregnant using natural remedies.

6. Pneumonia

Pneumonia is a lung infection that can be caused by viruses, bacteria, or fungi. It leads to symptoms such as a high-grade fever, chills, dry cough, phlegm, shortness of breath and chest pain.

What to do: Treatment for pneumonia should be carried out as guided by an obstetrician, who may prescribe antibiotics to treat the infection and acteaminophen to manage the fever.

7. Listeriosis

Listeriosis is an infection caused by Listeria monocytogenes bacteria, which is transmitted through contaminated food and water, such as unpasteurized milk, fish, raw meat, vegetables or processed foods. A listeria infection can cause symptoms such as a high-grade fever, body pain and chills, which can be confused with the flu.

Although a listeria infection is rare, during pregnancy women are more at risk of having the infection, due to their weakened immune system.

What to do: listeriosis is treated with antibiotics as prescribed by an obstetrician. It is also important to drink plenty of water to prevent dehydration, and to maintain a light, easily digestible diet.

During pregnancy, as a way to prevent listeriosis, pregnant women should avoid eating raw or undercooked meat, fish or unpasteurized milk. Be sure to thoroughly wash fruits and vegetables before handling and consuming them.

8. Toxoplasmosis

Toxoplasmosis is an infection caused by Toxoplasma gondii (T. gondii) parasites. These can be transmitted to pregnant women following contact with contaminated soil or cat feces, or consumption of undercooked or poorly sanitized meat from animals contaminated by the parasite.

Most of the time, toxoplasmosis does not cause obvious symptoms, however, some women may experience a low-grade fever, swelling in the neck, headache and general malaise.

What to do: Toxoplasmosis should be diagnosed as quickly as possible by the obstetrician so that antibiotic treatment can be started immediately. Prompt treatment can treat the mother and reduce the risk of transmission to the baby, preventing complications.

9. Cytomegalovirus

Cytomegalovirus is a virus from the herpes family, which can cause infection in pregnant women and symptoms such as fever above 38ºC (or 100.4ºF), muscle pain, inflammation and armpit pain.

During pregnancy, this virus is detected through prenatal exams, and is generally harmless to the mother and baby, if the woman was infected before becoming pregnant. However, when a woman becomes infected during pregnancy, the virus can cause problems such as microcephaly and deafness in the baby, as it can pass to the baby through the placenta.

What to do: prenatal exams should be carried out as ordered by the obstetrician to assess whether the woman has a cytomegalovirus infection. This way, treatment with antivirals can be recommended as needed.

10. COVID-19

COVID-19 is a viral respiratory infection that causes symptoms like fever, chills, sore throat, dry cough, excessive fatigue, loss of smell or taste, and a blocked or runny nose.

During pregnancy, there is a greater risk for women developing a serious illness, as her immune system is more weakened.

What to do: it is important to isolate yourself if you suspect you may have COVID-19, and to complete a rapid COVID test or PCR test as ordered by your obstetrician to confirm the infection. If necessary, the doctor may prescribe medication to help relieve, although more serious cases may require for maternal and fetal monitoring.

11. Ectopic pregnancy

A fever that presents at the beginning of pregnancy, up to 14 weeks of gestation, may be a sign of an ectopic pregnancy. This condition will typically present with intense pain in the lower abdomen, and can be confirmed with an ultrasound.

An ectopic pregnancy occurs when the embryo develops outside of the uterus, with most occurring in the fallopian tubes. It can also cause other symptoms such as intense cramping on only one side of the belly that worsens with movement, dizziness, vaginal bleeding, pain during sex, nausea, vomiting or fainting.

What to do: If you notice symptoms of an ectopic pregnancy, you should proceed immediately to the nearest emergency room for testing, diagnosis and treatment as needed. Treatment usually involves surgical removal of the embryo.

Can a fever during pregnancy harm the baby?

A fever above 39ºC (or 102.2ºF) during pregnancy can harm the baby and even lead to premature birth. The fever and rise in temperature in itself does not harm the baby, but the infection causing the fever may put the baby at risk.

Therefore, if you experience a fever, you should speak to your OBGYN or seek medical assistance for assessment and possible treatment.

When to see a doctor

It is important for pregnant women to consult their obstetrician whenever a fever appears during pregnancy and does not improve within 24 hours with rest and hydration.

In addition, you should seek medical attention or proceed to the nearest emergency room in the following situations:

Fever that appears for no apparent reason
Temperature reaches 39ºC (or 102.2ºF) very suddenly
Chills
Headache
Malaise
Nausea or vomiting
Diarrhea
Abdominal pain
Intense headache
Shortness of breath or difficulty breathing
Pain or burning when urinating
Vaginal bleeding or discharge
Loss of amniotic fluid
Lightheadedness

If you are experiencing diarrhea and/or vomiting, it is also important to drink water, electrolyte solutions, soup and broths to replace any fluid and mineral losses.

Treatment options

Fever medicine such as acetaminophen should only be taken as prescribed, as it is important to identify the cause of the fever.

Acetaminophen is the only medication that is indicated during pregnancy to reduce fever.

Teas to reduce fever during pregnancy

Teas should not be used without your doctor's approval during pregnancy as they may not always be safe for consumption. Although they are made with medicinal plants, some can promote uterine contraction and vaginal bleeding, which can put the baby at risk.

You can opt to drink just one cup of very hot chamomile tea to promotes sweating and lower a fever naturally.