ACOG FAQs for Patients Concerning Influenza (Flu) Vaccination During Pregnancy

I am pregnant. Should I get the influenza vaccine (flu shot)?

Yes. Getting a flu shot is the best way to protect you and your baby from serious illness from the flu. Pregnant women and their fetuses have a higher risk of serious complications from the flu. The flu shot given during pregnancy protects women and their newborns. You need a flu shot each year because the flu viruses targeted by the vaccine can change from year to year. The flu shot has been safely given to millions of pregnant women for many years.

How does my flu shot protect my newborn?

When you get a flu shot, your body makes antibodies that also pass to your fetus. This means your baby has protection against the flu after birth. This is important because infants less than 6 months of age are too young to get the flu shot.

Why is it important for pregnant women to get the flu shot?

The flu is a mild-to-severe illness that also often includes fever, body aches, sore throat, cough, and fatigue. Pregnant women who get the flu can become much sicker than women who get the flu when they are not pregnant. Pregnant women who get the flu have a higher chance of the flu turning into pneumonia than women who are not pregnant. Pneumonia is a serious infection in the lungs that usually requires treatment in the hospital. Pregnant women who get the flu often need more medical visits and frequently need to be admitted to the hospital for observation and treatment.

During which trimester is it safe to get a flu shot?

The flu shot can be safely given during any trimester. Pregnant women can get the flu shot at any point during the flu season (typically October through May). Pregnant women should get the shot as soon as possible when it becomes available. If you are pregnant, talk with your obstetrician–gynecologist (ob-gyn) or other health care provider about getting the flu shot.

Which flu vaccine should pregnant women get?

Pregnant women should receive any licensed, recommended, age-appropriate inactivated flu vaccine. The Advisory Committee on Immunization Practices and the American College of Obstetricians and Gynecologists do not recommend one type of flu shot over another.

Will the flu shot give me the flu?

No. You cannot get the flu from getting the flu shot.

I got the flu shot, so why did I still get sick?

The flu shot does not protect against all strains of the flu virus. Experts do their best to determine the virus strains that are most likely to cause illness the following season. Sometimes additional strains end up causing illness. After your flu shot, it takes about 2 weeks for your body to develop antibodies, which are what protects you from the flu. So, if you are exposed to the flu during the time immediately after your flu shot, you can still get the flu. That is why it is important to get the flu shot before flu season becomes very active. The flu shot does not protect against the common cold or other respiratory viruses. During the flu season, you can still get a respiratory illness that is not the flu, even though you got a flu shot.

What are the side effects of the flu shot?

Low-grade fevers, headaches, and muscle aches can occur as temporary (1–2 days) side effects in some people after getting the flu shot. According to the Centers for Disease Control and Prevention, these risks are outweighed by the risks of the flu, which is a serious illness that can make you or your baby seriously ill for much longer.

Is there any reason I should not get the flu shot?

There are very few reasons that a pregnant woman should not get a flu shot. A history of egg allergy, including hives, is not a reason to avoid the flu shot. However, if you have had a severe allergic reaction after a previous flu shot, you should not get another flu shot. Talk with your ob-gyn or other health care provider about any reactions you may have had with past flu shots.

Are preservatives in flu vaccines safe for my baby?

Yes. Thimerosal is a mercury-containing preservative used in very small amounts in some flu shots. There is no scientific evidence that thimerosal causes health or developmental problems for pregnant women or children born to women who received thimerosal-containing shots during pregnancy. Thimerosal-free types of the flu shot also are available. Pregnant women can get the flu shot with or without the preservative.

What else can I do to keep my baby healthy and free of the flu?

Getting your flu shot while you are pregnant is the best step in protecting yourself and your fetus against the flu. Data show that babies born to women who got the flu shot while pregnant have much lower rates of flu compared with babies whose mothers did not get the shot. Breastfeeding your baby and making sure family members and caregivers get the flu shot also will protect your baby.

I am breastfeeding my baby. Is it safe for me to get the flu shot?

Yes. It is safe and recommended if you did not get a flu shot during pregnancy. The antibodies your body makes after the flu shot can be passed to your baby through breast milk. This reduces your baby’s chance of getting sick with the flu.

Is it safe to get a flu shot at my local pharmacy?

Yes. Pharmacists are well trained to give immunizations. Flu shots are available at most major pharmacies. You can find a location for a flu shot at This is a good option if your ob-gyn or other health care provider does not offer the flu shot in his or her office. Be sure to let your ob-gyn or other health care provider know when you have gotten the flu shot so that your medical record can be updated. The pharmacy also should provide you with documentation of your flu shot.

What should I do if I think I have the flu?

Although the flu shot is the most effective way to prevent the flu, there is still a chance you might get the flu. If you think you have the flu, contact your ob-gyn or other health care provider right away. Be sure to tell your health care provider that you are pregnant. If you have severe symptoms, such as a fever higher than 100.0°F and trouble breathing, dizziness when standing, or pain in your chest, contact your ob-gyn or other health care provider and seek immediate medical attention. You also should contact your ob-gyn or other health care provider if you have had close contact with someone likely to have been infected with the flu.

Can I get the tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis shot and flu shot at the same time?

Yes. You can get the tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) shot and the flu shot in the same visit. Receiving these shots at the same time is safe and effective.




American College of Obstetricians and Gynecologists
Immunization for Women: Influenza Overview for Patients

American College of Obstetricians and Gynecologists
Immunization for Women

Centers for Disease Control and Prevention
Seasonal influenza: Pregnant Women and Influenza (Flu)

Department of Health and Human Services
Pregnant Women

Also available in Spanish


Updated 5/31/18

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