Fever during pregnancy

A fever is defined as an above-normal body temperature, or any temperature higher than 38°C. Fever during pregnancy is usually a sign of infection (e.g., urinary tract infection, listeriosis, fifth disease, measles, cold, flu).

Can a fever be dangerous for the fetus?

During pregnancy, even a mild fever should be monitored closely. A low-grade fever lasting more than 24 hours or a fever of 38.5°C or higher can be harmful to the pregnancy, as it may indicate an infection. Infections are a common cause of preterm birth.

Should I consult a doctor if I have a fever?

It’s best to consult a doctor in the following cases:

• You have a fever, even if it’s mild, and no symptoms that might suggest you have a cold.
• Your fever is related to a cold and lasts more than 24 hours (oral temperature of 38°C–38.4°C).
• Your oral temperature (taken twice) is 38.5°C or higher.
• You’re experiencing severe chills.
• You’re showing signs of dehydration (e.g., intense thirst, dark urine and decreased urine output).
• You have a fever and notice that your vaginal secretions have increased or have a bad smell.
• You have a fever and a chronic condition (e.g., diabetes, asthma).
• You have a fever and notice a decrease in your baby’s movements.

When in doubt, call Info-Santé (811) or contact your health care provider. You can also consult your pharmacist. If you are more than 16–20 weeks pregnant, you can also call the obstetrics department of the hospital where you plan to give birth.

How do you treat a low-grade fever?

If the fever is caused by a bacterial infection, your doctor will prescribe antibiotics. If a virus is to blame, you’ll most likely have to wait for the infection to heal on its own. Either way, it’s important to stay hydrated.

You can also take acetaminophen (e.g., Tylenol^®, Atasol^®) to bring your fever down.That said, you should avoid taking ibuprofen (e.g., Advil^®, Motrin^®) without first discussing it with the health care professional who’s following your pregnancy, as it isn’t safe to take ibuprofen for the entire length of your pregnancy. In fact, taking ibuprofen during the first few weeks may be associated with an increased risk of miscarriage, and taking it during the third trimester could damage to your baby’s kidneys and heart.

Is it possible to prevent fever during pregnancy?

The best way to prevent fever is to avoid infections. Effective preventive measures include the following:

• Wash your hands often.
• Avoid close contact with people who are sick whenever possible.
• Get the flu shot.

Things to keep in mind

• Fever during pregnancy is often a sign of infection.
• It’s usually a good idea to consult a doctor to determine what’s causing the fever and how to treat it.
• Acetaminophen can be used to bring down a fever during pregnancy.

Scientific review: Dr. Chantal Ouellet, family doctor Research and copywriting: The Naître et grandir team Updated: September 2021

Photo: 123rf.com/Iakov Filimonov