Influenza (flu) and pregnancy

What is the flu?

Influenza (also called flu) is a virus that can cause serious illness. It’s more than just a runny nose and sore throat. The flu can make you very sick, and it can be especially harmful if you get it during or right after pregnancy.

How does the flu spread?

The flu spreads easily from person to person. When someone with the flu coughs, sneezes or speaks, the virus spreads through the air. You can get infected with the flu if you breathe it in or if you touch something (like a door handle or a phone) that has the flu virus on it and then touch your nose, eyes or mouth.

People with the flu may be able to infect others from 1 day before they get sick up to 5 to 7 days after. People who are very sick with the flu or young children may be able to spread the flu longer, especially if they still have symptoms.

How can the flu harm your pregnancy?

Health complications from the flu, like a lung infection called pneumonia, can be serious and even deadly, especially if you’re pregnant. If you get the flu during pregnancy, you’re more likely than other adults to have serious complications. It’s best to get a flu shot before you get pregnant. Getting a flu shot can help reduce your risk of getting the flu, having serious flu complications and needing treatment in a hospital.

Pregnant women who get the flu are more likely than women who don’t get it to have preterm labor (labor that happens before 37 weeks of pregnancy) and preterm birth (birth that happens before 37 weeks of pregnancy. Fever from the flu may be linked to birth defects, like neural tube defects, and other problems in your baby. A birth defect is a health condition that is present at birth. Birth defects change the shape or function of one or more parts of the body. They can cause problems in overall health, how the body develops, or in how the body works. Neural tube defects are birth defects of the brain and spinal cord.

How does the flu shot help protect you from flu?

The flu shot contains a vaccine that helps prevent you from getting the flu. The flu shot can’t cause the flu. It’s safe to get a flu shot any time during pregnancy, but it’s best to get it before flu season (October through May). Even though you’re more likely to get the flu during flu season, you can get it any time of year.

There are many different flu viruses, and they’re always changing. Each year a new flu vaccine is made to protect against three or four flu viruses that are likely to make people sick during the upcoming flu season. Protection from a flu shot only lasts about a year, so it’s important to get a flu shot every year. You can get the shot from your health care provider, and many pharmacies and work places offer it each fall. Use the HealthMap Vaccine Finder to find out where you can get the flu vaccine.

Is it safe to get a flu shot during pregnancy?

It’s safe for most pregnant women to get the flu shot. Tell your health care provider if you have any severe allergies or if you’ve ever had a severe allergic reaction to a flu shot. Severe allergic reactions to flu shots are rare. If you’re worried about being allergic to the flu shot, talk to your provider to make sure it’s safe for you.

Some flu vaccines are made with eggs. Most women with egg allergies can get the flu shot. But if you have severe egg allergies, get the shot in a medical setting (like a doctor’s office, hospital or clinic) from a provider who knows how to treat severe allergies and allergic reactions.

Pregnant women should not get the flu nasal spray. This is a spray that’s put in your nose.

What are signs and symptoms of the flu?

Signs of a condition are things someone else can see or know about you, like you have a rash or you’re coughing. Symptoms are things you feel yourself that others can’t see, like having a sore throat or feeling dizzy. Common signs and symptoms of the flu include:

• Being very tired or sleepy (also called fatigue)
• Cough
• Fever (100 F or above), chills or body shakes. Not everyone who has the flu has a fever.
• Headache, or muscle or body aches
• Runny or stuffy nose
• Sore throat
• Vomiting (throwing up) or diarrhea (more common in children)

The flu often comes on quickly. Fever and most other symptoms can last a week or longer. But some people can be sick from the flu for a long time, including children, people older than 65, pregnant women and women who have recently had a baby.

Call 911 and get medical care right away if you have any of these signs or symptoms:

• Feeling your baby move less or not at all
• High fever that doesn’t go down after taking acetaminophen (Tylenol®). Don’t take any medicine without checking with your provider first.
• Pain or pressure in the chest or belly
• Sudden dizziness or confusion
• Trouble breathing or shortness of breath
• Vomiting that’s severe or doesn’t stop
• Flu signs or symptoms that get better but then come back with fever and a worse cough

How is the flu treated during pregnancy?

If you think you have the flu even if you’ve been vaccinated, call your health care provider right away. Your provider may prescribe an antiviral medicine to help prevent or treat the flu. Antivirals kill infections caused by viruses. They can make your flu milder and help you feel better faster. Antivirals also can help prevent serious flu complications, like pneumonia. For flu, antivirals work best if you take them within 2 days of having symptoms. Quick treatment with antiviral medicine can help prevent serious flu complications.

If you’ve had close contact with someone who has the flu during your pregnancy or in the 2 weeks after giving birth, tell your health care provider. Even if you don’t have signs or symptoms of flu, your provider may want to treat you with an antiviral medicine to help prevent you from getting the flu and having serious complications.

Three medicines are approved in the United States to prevent or treat the flu in pregnant women and women who recently had a baby. Talk to your provider about which one is right for you:

1. Oseltamivir (brand name Tamiflu®).This medicine comes as a capsule or liquid.
2. Zanamivir (brand name Relenza®). This medicine is a powder that you breathe in by mouth. It isn’t recommended for people with breathing problems, like asthma.
3. Peramivir (Rapivab®). This medicine is given through a needle into a vein (also called IV) by a health care provider.

If you have a fever, call your provider as soon as possible. Before taking any over-the-counter medication, be sure to check with your provider first. Not all medication is safe to take during pregnancy. If you have the flu, get lots of rest and drink plenty of fluids. You may not want to eat much. Try eating small meals to help your body get better.

How can you stop the flu from spreading?

When you have the flu, you can spread it to others. Here’s what you can do to help prevent it from spreading:

• Stay home when you’re sick and limit contact with others.
• Cough or sneeze into a tissue or into your arm. Throw used tissues in the trash.
• Try not to touch your eyes, nose or mouth.
• Wash your hands with soap and water before touching anyone. You also can use alcohol-based hand sanitizers. Use enough hand sanitizer so that it takes at least 15 seconds for your hands to dry.
• Wash your dishes and utensils well with hot soapy water, or in a dishwasher if you have one.
• Don’t share your dishes, glasses, utensils or toothbrush.

Why is the flu so harmful during pregnancy?

The flu can be dangerous during pregnancy because pregnancy affects your immune system, heart and lungs. Your immune system is your body’s way of protecting itself from illnesses and diseases. When your body senses something like a virus that can harm your health, your immune system works hard to fight the virus.

When you’re pregnant, your immune system isn’t as quick to respond to illnesses as it was before pregnancy. A lowered immune system means you’re more likely get sick with viruses like the flu.

During pregnancy, your lungs need more oxygen, especially in the second and third trimesters. Your growing belly puts pressure on your lungs, making them work harder in a smaller space. You may even find yourself feeling shortness of breath at times. Your heart is working hard, too. It’s busy supplying blood to you and your baby. All of this means your body is stressed during pregnancy. This stress on your body can make you more likely to get the flu. If you’re pregnant or had a baby within the last 2 weeks, you’re more likely than other women to have serious health problems from the flu.

More information

Centers for Disease Control and Prevention Flu & Pregnancy

Flu.gov

What is the Flu? Common Influenza Questions (familiesfightingflu.org)

Last reviewed: November, 2022