Pregnancy and the Flu
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 pregnant women and women up to 2 weeks postpartum 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 or 38.3°C, chills, sweating, muscle aches, headache, runny nose, cough, sore throat), call your doctor. With proper care, serious complications can be prevented.
Is the Flu Shot Safe During Pregnancy?
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.
Getting a Flu 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 have not been sick with the flu yet. 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.
It is estimated that an average of 1 to 2 hospitalizations could be prevented each year for every 1,000 pregnant women who get the flu vaccine.
Centers for Disease Control and Prevention http://www.cdc.gov
US Food and Drug Administration http://www.fda.gov
Public Health Canada http://www.phac-aspc.gc.ca
Women's Health Matters http://www.womenshealthmatters.ca
Centers for Disease Control and Prevention. Prevention and control of influenza: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR. 2005;54(No. RR-8).
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Influenza in pregnancy. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated August 14, 2015. Accessed February 2, 2016.
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 February 1, 2016. Accessed February 2, 2016.
Key facts about flu vaccine. Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/flu/keyfacts.htm. Updated August 7, 2015. Accessed February 2, 2016.
Munoz FM, Greisinger AJ, Wehmanen OA, et al. Safety of influenza vaccination during pregnancy. Am J Obstet Gynecol. 2005;192:1098-1106.
Neuzil KM, Reed GW, Mitchel EF, et al. Impact of influenza on acute cardiopulmonary hospitalizations in pregnant women. Am J Epidemiol. 1998;148:1094-1102.
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 February 2014. Accessed February 2, 2016.
Pregnant women & influenza (flu). Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/flu/protect/vaccine/pregnant.htm. Updated December 10, 2015. Accessed February 2, 2016.
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 October 16, 2015. Accessed February 2, 2016.
1/30/2014 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed: Safety of influenza A (H1N1) 2009 live attenuated monovalent vaccine in pregnant women. Obstet Gynecol. 2013 Dec;122(6):1271-8.
- Reviewer: Michael Woods, MD
- Review Date: 01/2016
- Update Date: 03/28/2014