Flu During Pregnancy: The Risks, the Flu Shot, and When to Get It

Influenza (flu) during pregnancy is more likely to cause illness serious enough to need hospital care. It may also affect a developing baby: fever, a common flu symptom, has been associated in some studies with neural tube defects and other harms.

If you are pregnant and have flu symptoms, call your health care provider right away. CDC recommends prompt antiviral treatment during pregnancy for anyone with confirmed or suspected flu.

Two people protected by one shot

A flu shot during pregnancy protects against flu and flu-related hospitalization — and it protects the baby too. The pregnant parent’s antibodies pass to the baby before birth, guarding against flu and flu hospitalization for several months after birth, when infants are too young to be vaccinated themselves. Vaccination while breastfeeding also produces antibodies that reach the baby through breast milk.

What the studies show:

• A 2013 study found that during the 2010–2011 and 2011–2012 seasons, vaccination cut the risk of flu during pregnancy by up to one-half — in line with flu vaccine effectiveness in adults aged 18–64.
• A 2018 study found that a flu vaccine during pregnancy reduced the risk of flu hospitalization by an average of 40%.

Which vaccine, and when

• Get the flu shot, not the nasal spray vaccine, during pregnancy.
• CDC recommends flu vaccination in any trimester.
• For most adults, September and October are good months to be vaccinated. In the third trimester, vaccination in July or August can also be considered, to help protect the baby for its first months.
• There is no requirement for special permission or written consent from your doctor to be vaccinated at a worksite clinic, pharmacy or other location — including for people with pre-existing medical conditions.

Safety

Flu shots have been given to millions of pregnant women over more than 50 years, with an excellent safety record, and substantial evidence shows they are safe for both mother and baby.

Other ways to lower the risk

• avoid people who are sick
• cover coughs and sneezes
• wash hands often
• clean frequently touched surfaces
• take steps for cleaner indoor air

Sources

Based on "Flu & Pregnancy," Centers for Disease Control and Prevention; a work of the United States government in the public domain.