Flu during pregnancy: Symptoms, prevention, and safe treatment options

Pregnancy brings immense joy, but it also comes with added vulnerability to infections like the flu. Due to changes in the immune system, lungs, and blood volume, expectant mothers are more prone to catching the flu and experiencing severe symptoms. Hence, flu during pregnancy can feel overwhelming, especially when you are unsure what’s safe for you and your baby. 

The good news is that with the right precautions, like vaccination, hygiene, and early treatment, you can significantly reduce your risk. Understanding flu symptoms during pregnancy, safe treatments, and prevention tips can help you stay healthy and protect your baby.

In this guide, we break down everything you need to know about flu during pregnancy, including when to call your doctor and how to manage symptoms safely.

What is flu during pregnancy?

Flu during pregnancy is a viral respiratory infection that can cause fever, cough, body aches, and fatigue. Pregnant women are at higher risk of complications because pregnancy affects the immune and respiratory systems. 

Influenza (flu) is a contagious respiratory disease caused by viruses that primarily infect the nose, throat, and, in some cases, the lungs too.

The changes in the immune system, heart, and lungs during pregnancy can make it harder for you to defend yourself against flu infections. You may also be more likely to experience severe symptoms, resulting in urgent hospitalizations and intensive care admissions.

Flu symptoms during pregnancy

Flu while pregnant can have a combination of the below symptoms:

• Fever
• Chills
• Cold and cough
• Sore throat
• Runny or stuffy nose
• Body aches
• Headaches
• Fatigue

Flu symptoms during pregnancy can appear suddenly and often take over rapidly within a short period. If you encounter any of these symptoms, act quickly and contact a healthcare professional for immediate diagnosis, possible treatment, and medication options. This helps ease symptoms, reduce illness duration, and improve results for both you and your baby.

Gastric flu during pregnancy

Gastric flu or stomach flu is usually a different virus affecting the digestive system, but it can still be uncomfortable during pregnancy. Gastric flu during pregnancy symptoms include:

• Nausea and vomiting
• Diarrhea
• Abdominal cramps
• Dehydration
• Fatigue

While gastric flu doesn’t pose any harm to your baby, if you cannot keep liquids down for 24 hours, experience diarrhea or vomiting lasting longer than 48 hours, high fever, severe abdominal cramps, blood in your stool or vomit, contact your healthcare provider immediately.

Why flu during pregnancy can be serious

Flu during pregnancy is more than just a seasonal illness. Because pregnancy affects the immune system, lungs, and heart, it can increase the risk of complications for both mom and baby. 

The points mentioned below are to highlight why prevention and early care matter. Just remember that most women recover fully.

1. Higher risk of hospitalization

Pregnant women are more likely to be hospitalized with the flu compared to non-pregnant adults because their immune system is naturally suppressed during pregnancy.

2. Increased chances of complications like pneumonia

Flu can lead to serious respiratory infections such as pneumonia, because lung capacity is already reduced as your baby grows.

3. Fever may affect baby’s development in early pregnancy

A high fever, common with flu, especially in early pregnancy, has been linked to a higher risk of certain birth defects, including neural tube defects.

4. Risk of preterm labor in severe cases

Severe flu infections can increase the risk of preterm labor and early delivery, especially if complications like high fever or infection occur.

5. Higher overall risk of pregnancy complications

Flu during pregnancy has also been associated with risks like low birth weight, miscarriage, and more severe illness in the mother in some cases.

Are flu shots during pregnancy safe?

Yes, the flu shot is safe during pregnancy and is recommended in any trimester. It helps protect both you and your baby, and can even reduce the risk of hospitalization. 

Over the years, numerous studies have consistently affirmed the excellent safety profile of flu vaccines among pregnant women and found positive maternal immunization outcomes. One of the studies by JAMA Pediatrics also demonstrates that vaccination during pregnancy can minimize the risk of flu-induced hospitalizations in infants by up to 39%.

Multiple studies have upheld that flu vaccines are safe across different fetal developmental stages, both for the mother and the baby. For example, a significant study, which employed the Vaccine Safety Datalink (VSD) project conducted by CDC, has found there is no increased risk of “spontaneous abortions or miscarriages” in women who get their flu shot during pregnancy as compared to those who remain unvaccinated. 

Benefits of flu shot during pregnancy:

• Reduces risk of severe illness
  
• Protects baby after birth through antibodies
  
• Lowers chances of hospitalization

You might have some side effects, but they are typically mild and short-lived, such as “feeling sore at the site of injection, low-grade fever, and body aches.” These side effects are very similar to those experienced by non-pregnant individuals when they receive the vaccine.

What is the best time to get the flu shot during pregnancy?

Centers of Disease Control and Prevention recommends that inactivated influenza vaccines (IIVs) can be given during any trimester of pregnancy, and they don’t cause any harm to the pregnant woman and her baby. 

However, if you are someone who likes to plan things, then September or October are typically good times for most adults to get vaccinated. After these months, flu activity begins to increase.

If you are in the third trimester of pregnancy, you can also consider vaccination in July and August. This helps protect your infant from the flu for several months after birth, as they are too young to be vaccinated immediately after birth.

How to prevent flu during pregnancy

These simple habits can significantly help you prevent flu during pregnancy or find relief in case you have already caught it.:

• Gargle with warm salt water.
• Take proper rest. 
• Focus on hydrating yourself with water (preferably warm) or herbal teas.
• You can also use nasal saline sprays.
• Try a humidifier in home spaces.
• Wash your hands frequently.
• Avoid close contact with sick people.
• Clean frequently touched surfaces.
• Avoid touching your face.
• Wear a mask in public places.

Tip: If soap and water aren’t available, use a hand sanitizer that has at least 60% alcohol content in it.

When to call your doctor

Seek medical help if you have:

• High fever that doesn’t improve
• Difficulty breathing
• Severe weakness or dizziness
• Symptoms that improve and then worsen

Conclusion

Flu during pregnancy can be uncomfortable and, in some cases, serious, but the right steps can make a big difference. From recognizing early symptoms to getting timely treatment, staying informed helps you protect both your health and your baby’s development.

The flu shot during pregnancy is not only safe but also one of the best ways to prevent severe illness and protect your baby after birth.

If you ever feel unsure about your symptoms or treatment options, reaching out to your healthcare provider can give you the reassurance and care you need during this important time.

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Sources:

1. Changes in the immune system. National Library of Medicine. 2011. The Immune System in Pregnancy: A Unique Complexity.
2. Immunity of pregnant women. National Library of Medicine. 2025. Preventing Influenza Virus Infection and Severe Influenza Among Pregnant People and Infants.
3. Flu symptoms during pregnancy. CDC. 2025. Recommendations for Obstetric Health Care Providers Related to Use of Antiviral Medications for the Treatment and Prevention of Influenza.
4. Influenza vaccinations. CDC. 2025. Influenza Vaccine Safety Considerations during Pregnancy or while Breastfeeding.
5. Maternal immunization outcomes. WHO. 2006. Influenza vaccination of women during pregnancy.
6. Flu-induced hospitalizations in infants. JAMA Pediatrics. 2023. Maternal Vaccine Effectiveness Against Influenza-Associated Hospitalizations and Emergency Department Visits in Infants.
7. No increased risk of “spontaneous abortions or preterm births. Harvard Health Publishing. 2017. Flu shots during pregnancy.