Pregnant Women & Influenza (Flu)
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 can also help protect a baby after birth from flu. (Mom passes antibodies onto the developing baby during her pregnancy.)
A Flu Vaccine is the Best Protection Against Flu
Getting a flu vaccine is the first and most important step in protecting against flu. Pregnant women should get a flu shot and not the live attenuated influenza vaccine (LAIV), also known as nasal spray flu vaccine. Flu vaccines given during pregnancy help protect both the mother and her baby from flu. Vaccination has been shown to reduce the risk of flu-associated acute respiratory infection in pregnant women by up to one-half. A 2018 study showed that getting a flu shot reduced a pregnant woman’s risk of being hospitalized with flu by an average of 40 percent. Pregnant women who get a flu vaccine are also helping to protect their babies from flu illness for the first several months after their birth, when they are too young to get vaccinated. A list of recent studies on the benefits of flu vaccination for pregnant women is available.
A Long Record of Safety for Flu Shots in Pregnant Women
Flu shots have been given to millions of pregnant women over many years with a good safety record. There is a lot of evidence that flu vaccines can be given safely during pregnancy; though these data are limited for the first trimester. CDC and ACIP recommend that pregnant women get vaccinated during any trimester of their pregnancy. It is very important for pregnant women to get the flu shot. More information about Seasonal Flu Vaccine Safety and Pregnant Women is available.
Other Preventive Actions
In addition to getting a flu shot, pregnant women should take the same everyday preventive actions CDC recommends of everyone, including covering coughs, washing hands often, and avoiding people who are sick.
Symptoms and Treatment
If you get sick with flu symptoms call your doctor right away. There are antiviral drugs that can treat flu illness and prevent serious flu complications. CDC recommends prompt treatment for people who have influenza infection or suspected influenza infection and who are at high risk of serious flu complications, such as people with asthma, diabetes (including gestational diabetes), or heart disease. Early treatment of influenza in hospitalized pregnant women has been shown to reduce the length of the hospital stay.
Flu symptoms include fever, cough, sore throat, runny or stuffy nose, body aches, headache, chills and fatigue. Some people may also have vomiting and diarrhea. People may be infected with the flu and have respiratory symptoms without a fever.
Early Treatment is Important for Pregnant Women
- Treatment should begin as soon as possible because antiviral drugs work best when started early (within 48 hours after symptoms start).
- Antiviral drugs can make your flu illness milder and make you feel better faster. They may also prevent serious health problems that can result from flu illness.
- Oral oseltamivir is the preferred treatment for pregnant women because it has the most studies available to suggest that it is safe and beneficial.
- Antiviral drugs require a prescription from your doctor.
- Having a fever caused by flu infection or other infections early in pregnancy may be linked to birth defects in a baby. In addition to taking antiviral drugs, pregnant women who get a fever should treat their fever with Tylenol® (or store brand equivalent) and contact their doctor immediately.
When to Seek Emergency Medical Care
If you are pregnant and have any of these signs, call 911 right away:
- Difficulty breathing or shortness of breath
- Pain or pressure in the chest or abdomen
- Sudden dizziness
- Severe or persistent vomiting
- High fever that is not responding to Tylenol® (or store brand equivalent)
- Decreased or no movement of your baby
Note: There is no recommendation for pregnant women or people with pre-existing medical conditions to get special permission or written consent from their doctor or health care professional for influenza vaccination if they get vaccinated at a worksite clinic, pharmacy or other location outside of their physician’s office. For more information, visit Misconceptions about Seasonal Flu and Flu Vaccines.
Additional Resources for Pregnant Women
Video & Podcasts
- Pregnant Women: Answers to Common Questions about the Flu Vaccine [Streaming, 5 min 43 sec]
- Preventing Flu During Pregnancy, A Cup of Health with CDC (3 MB, 3 min 38 sec)
- Preventing Flu During Pregnancy, A Minute of Health with CDC (1 MB, 59 sec)
- Flu Vaccination Videos for Kids, Parents and Pregnant Women
For Health Care Professionals
- Letter to Health Care Providers of Pregnant Women – 2017-2018 Flu Season [497 KB, 2 pages]
- New England Journal of Medicine Perspective, “2009 H1N1 Influenza and Pregnancy — 5 Years Later”
- ACIP Recommendations: Influenza Vaccination for Pregnant Women*
*Information included in the 2013-2014 ACIP seasonal influenza recommendations regarding the use of influenza vaccines in pregnant women should be considered current for the 2015-2016 influenza season.
Pregnant Women & Flu Vaccine Studies
- Study: Influenza Vaccine Effectiveness in Preventing Influenza-Associated Hospitalizations during Pregnancy: A Multi-Country Retrospective Test Negative Design Study, 2010-2016. Clinical Infectious Diseases. 2018
- Study: Influenza Vaccination of Pregnant Women and Protection of Their Infants The New England Journal of Medicine. 2014
- Study: Maternal immunisation with trivalent inactivated influenza vaccine for prevention of influenza in infants in Mali: a prospective, active-controlled, observer-blind, randomised phase 4 trial. The Lancet Infectious Diseases. 2016
- Study: Effectiveness of seasonal trivalent influenza vaccine for preventing influenza virus illness among pregnant women: a population-based case-control study during the 2010-2011 and 2011-2012 influenza seasons. Clinical Infectious Diseases. 2014
- Study: Effectiveness of maternal influenza immunization in mothers and infants. The New England Journal of Medicine. 2009
- Study: Year-round influenza immunisation during pregnancy in Nepal: a phase 4, randomised, placebo-controlled trial. The Lancet Infectious Diseases. 2017
- Study: Benefit of Early Initiation of Influenza Antiviral Treatment to Pregnant Women Hospitalized with Laboratory-Confirmed Influenza The Journal of Infectious Diseases. 2016
- Page last reviewed: October 22, 2018
- Page last updated: October 22, 2018
- Content source:
- Centers for Disease Control and Prevention, National Center for Immunization and Respiratory Diseases (NCIRD)
- Page maintained by: Office of the Associate Director for Communication, Digital Media Branch, Division of Public Affairs