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Pregnancy and the Influenza Vaccine

Influenza (flu) is more likely to cause severe illness in pregnant women than in women of reproductive age who are not pregnant. Changes in the immune system, heart, and lungs during pregnancy make pregnant women (and women up to two weeks postpartum) more prone to severe illness from flu, including illness resulting in hospitalization. Flu also may be harmful for a pregnant woman’s developing baby. A common flu symptom is fever, which may be associated with neural tube defects and other adverse outcomes for a developing baby. Getting vaccinated also can help protect a baby after birth from flu. (Mom passes antibodies onto the developing baby during her pregnancy.)


Is it safe for pregnant women and their developing babies to get a flu shot?

Yes. Flu shots have been given to millions of pregnant women over many years with a good safety record. There is a large body of scientific studies that supports the safety of flu vaccine in pregnant women and their babies. CDC continues to gather data on this topic.


Can flu vaccination result in miscarriage?

Multiple studies have shown that women who have gotten flu shots during pregnancy have not had a higher risk for spontaneous abortion (miscarriage). One of the largest and strongest studiesexternal icon was conducted in CDC’s Vaccine Safety Datalink (VSD) project. The recently published study covered three flu seasons (2012-13, 2013-14, 2014-15) looking for any increased risk for miscarriage among pregnant women who had received a flu vaccine during their pregnancy. The study found NO increased risk for miscarriage after flu vaccination during pregnancy. This study was conducted in follow-up to a previous smaller study. The prior studyexternal icon examined data from the 2010-2011 and 2011-2012 flu seasons and identified an association between flu vaccination early in pregnancy and an increased risk of spontaneous abortion or miscarriage; particularly among women who had received flu vaccine during the previous flu season. However, the study had several limitations, including small sample size which could have led to imprecise results. This study was the only analysis to show that association; no other studies had found an increased risk of SAB following flu vaccination At this time, the Advisory Committee on Immunization Practices (ACIP), the American College of Obstetricians and Gynecologists (ACOG)Externalexternal icon and CDC continue to recommend that pregnant women get a flu vaccine during any trimester of their pregnancy because flu poses a danger to pregnant women and a flu vaccine can prevent serious illness, including hospitalization, in pregnant women.

A fact sheet with more information on this topic is available. Any pregnant woman who has questions about vaccines should talk to her doctor.


What side effects have pregnant women experienced from flu shots?

The most common side effects experienced by pregnant women are the same as those experienced by other people. They are generally mild and include:

  • Soreness, redness, and/or swelling from the shot

  • Fainting

  • Headache

  • Fever

  • Muscle aches

  • Nausea

  • Fatigue

If side effects occur, they usually begin soon after the shot is given and generally last for 1-2 days.

Rarely, flu shots can cause serious problems like severe allergic reactions. Anyone with a severe, life-threatening allergy to any of the vaccine ingredients should not get the shot.


Can pregnant women with egg allergies get vaccinated?

Most people who have an allergy to eggs can get vaccinated, with some additional safety measures. A person with severe (life-threatening) allergy to any vaccine component, including egg pro