Pregnant Women & Influenza (Flu)
If you're pregnant, a flu shot is your best protection against serious flu illness. Vaccination helps protect women during and after pregnancy and also protects the baby for several months after birth.
The Flu and Pregnant Women
Flu is more likely to cause severe illness in pregnant women than in women who are not pregnant. Changes in the immune system, heart and lungs during pregnancy make pregnant women more prone to developing severe illness from flu, which can lead to hospitalization or even death. There also is some evidence to suggest that a pregnant woman sick with the flu has a greater chance of certain pregnancy complications and that a flu vaccine can lessen that risk. Watch a short video that explains why!
A Flu Shot Is the Best Protection Against Flu
Getting a flu shot is the first and most important step in protecting against flu. When given during pregnancy, flu shots have been shown to protect the mother and her baby after birth from flu. If you get vaccinated during pregnancy, your baby will be born with some flu antibodies that will help protect them from flu for several months. This is important because babies younger than 6 months can't get vaccinated yet, but they are at high risk of being hospitalized from the flu. An additional way to protect your baby after birth is for all of the baby's caregivers and close contacts (including brothers and sisters, grandparents and babysitters) to get vaccinated against the flu. Learn more about the importance of flu vaccination for pregnant women[512 KB]. Recent studies support the benefits of flu vaccination for pregnant women and their babies, including:
- A study that looked at flu vaccine effectiveness in pregnant women found that vaccination reduced the risk of flu-associated acute respiratory infection in pregnant women by about one half.1
- Another study found that babies of women who got a flu vaccine during their pregnancy were about one-third less likely to get sick with flu than babies of unvaccinated women. This protective benefit was observed for up to four months after birth.2
You can get a flu shot during any trimester of your pregnancy. (The nasal spray vaccine is not recommended for anyone during 2016-2017, but it has never been approved for use in pregnant women.)
Flu Shots Are Safe for Pregnant Women
Flu shots are a safe way to protect pregnant women from serious flu complications like pneumonia. Flu shots have been given to millions of pregnant women over many years. Flu shots have not been shown to cause harm to pregnant women or their babies. The shot is safe to get during any trimester. The side effects that can occur from a flu shot, like soreness or redness where the shot is given, are very minor compared to the serious problems that flu illness could cause for pregnant women and their babies.
Some pregnant women are worried about trace amounts of thimerosal in flu shots. Thimerosal is a mercury-based preservative that has been used for decades in the United States in multi-dose vials (vials containing more than one dose) of some vaccines to prevent their contamination with germs, bacteria and fungi. Some flu shots produced for the United States each flu season come in multi-dose vials, and contain thimerosal to safeguard against possible contamination of the vial once it is opened. Manufacturers also make single-dose flu shots without thimerosal. The single-dose units are made without thimerosal as a preservative because they are intended to be opened and used only once. While the most recent and rigorous scientific research shows that thimerosal-containing vaccines are not harmful, if you are worried about thimerosal, ask your doctor or other health care professional for a thimerosal-free flu shot. Manufacturers project that between 157 and 168 million doses of injectable influenza vaccine will be produced for the U.S. market this season; approximately 120 million doses of these will be thimerosal-free influenza vaccine.
Other Preventive Actions
In addition to getting the flu shot, pregnant women should take additional everyday preventive actions.
An additional way to protect the baby is for all the baby's caregivers and close contacts (including parents, brothers and sisters, grandparents and babysitters) to get vaccinated against the flu.
Early Treatment Is Important for Pregnant Women
If you get sick with flu symptoms call your doctor right away. There are prescription antiviral drugs that can treat flu illness and prevent serious flu complications. CDC recommends that pregnant women with flu symptoms be treated with these drugs.
When to Seek Emergency Medical Care
If you 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
- Thompson MG, Li DK, Shifflet P, et al. 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. Clin Infect Dis. 2014; 58(4):449-57.
- Tapia MD, Sow SO, Boubou T, et al. 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. Lancet Infect Dis. 2016; 3099(16):30054-8.