The Flu Shot and PregnancyEn Español (Spanish Version)
Over 200,000 people in the United States are hospitalized each year from complications of influenza
(the flu). Research has shown that pregnant women are at increased risk for serious complications of the flu. Since the best way to protect against the flu is to get vaccinated before flu season, the Centers for Disease Control and Prevention (CDC) recommends that all women who will be pregnant or who are pregnant during the flu season be vaccinated.
A number of factors make pregnant women more likely to have complications associated with the flu. For instance, pregnant women’s hearts are working harder, they have decreased lung capacity, and their immunity may be compromised.
Pregnant women who get the flu are at greater risk for serious illness and even death. If you experience flu symptoms (fever over 101ºF, chills, sweating, muscle aches, headache, runny nose, cough, sore throat), call your doctor. With proper care, serious complications can be prevented.
Studies have shown that flu shots are not associated with adverse effects on pregnancy outcomes including loss of pregnancy, preterm birth, or birth defects.
The CDC has approved the use of the flu shot for pregnant women. The flu shot contains an inactivated flu virus. However, the nasal-spray flu vaccine, which contains live, weakened flu viruses, is not approved for pregnant women. So if you are pregnant, make sure you get a flu shot, not the nasal spray vaccine.
Since the flu season in North America can begin as early as October and last as late as May, October is the best time to get a flu shot, but you can still get vaccinated any time during the flu season. If you are pregnant or plan to become pregnant during this year’s flu season, talk to your doctor in advance about getting a flu shot. It's important to note that, in some years, there is not always enough vaccine for everyone who needs one, especially early in the season. However, the CDC and state public health departments prioritize vaccinating pregnant women.
Once vaccinated, you most likely will have no serious problems. However, complications may occur. Minor side effects include soreness, redness, or swelling at the injection site; low-grade fever; and aches. More serious complications, such as severe allergic reactions, may occur on rare occasions.
estimated that an average of one to two hospitalizations could be prevented each year for every 1,000 pregnant women who get the flu vaccine.
Centers for Disease Control and Prevention
US Food and Drug Administration
Centers for Disease Control and Prevention. Prevention and control of influenza: recommendations of the Advisory Committee on Immunization Practices (ACIP).
Fiore AE, Uyeki TM, Broder K, Finelli L, Euler GL, Singleton JA, Iskander JK, et al. Prevention and control of influenza with vaccines: recommendations of the Advisory Committee on Immunization Practices (ACIP), 2010. Centers for Disease Control and Prevention (CDC). MMWR Recomm Rep. 2010;59(RR-8):1-62.
Influenza in pregnancy. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated February 28, 2014. Accessed March 27, 2014.
It's not too late to get your flu vaccine. Centers for Disease Control and Prevention website. Available at: http://cdc.gov/Features/FluPrevention/. Updated January 27, 2014. Accessed March 27, 2014
Key facts about flu vaccine. Centers for Disease Control and Prevention website. Available at:
http://www.cdc.gov/flu/keyfacts.htm. Updated September 26, 2013. Accessed March 27, 2014.
Munoz FM, Greisinger AJ, Wehmanen OA, et al. Safety of influenza vaccination during pregnancy.
Am J Obstet Gynecol.
Neuzil KM, Reed GW, Mitchel EF, et al. Impact of influenza on acute cardiopulmonary hospitalizations in pregnant women.
Am J Epidemiol.
Pregnancy: respiratory infections during pregnancy. American Academy of Family Physicians website. Available at:
http://familydoctor.org/familydoctor/en/diseases-conditions/colds-and-the-flu/respiratory-infections-during-pregnancy.html. Updated November 2010. Accessed June 4, 2012.
Pregnant women & influenza (flu). Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/flu/protect/vaccine/pregnant.htm. Updated February 4, 2014. Accessed March 27, 2014.
Thimerosal and 2013-2014 seasonal flu vaccines. Centers for Disease Control and Prevention website. Available at:
http://www.cdc.gov/flu/about/qa/thimerosal.htm. Updated September 3, 2013. Accessed March 27, 2014.
1/30/2014 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed/what.php: Safety of influenza A (H1N1) 2009 live attenuated monovalent vaccine in pregnant women. Obstet Gynecol. 2013 Dec;122(6):1271-8.
Last Reviewed March 2014