Is it safe to get a flu shot during pregnancy?

Answers from Roger W. Harms, M.D.

Yes, it's safe to get a flu (influenza) shot during pregnancy. In fact, the Centers for Disease Control and Prevention recommends a flu shot for anyone who's pregnant during flu season — typically early October through late March.

A flu shot during pregnancy can help:

  • Prevent the flu and maternal complications. Pregnancy puts extra stress on your heart and lungs. Pregnancy can also affect your immune system. These factors increase the risk of becoming severely ill due to the flu.
  • Prevent potential pregnancy problems due to the flu. Flu during pregnancy seems to increase the risk of miscarriage, premature birth and low birth weight.
  • Protect your baby after birth. Infants are at increased risk of severe flu symptoms, but childhood flu vaccines can't begin until a baby is 6 months old. If you have a flu shot during pregnancy, however, the antibodies you develop will pass through the placenta to help protect your baby from the flu. In a recent study, babies whose mothers had a flu shot during pregnancy were nearly 50 percent less likely to be hospitalized with the flu during their first flu season than were babies of unvaccinated mothers.

When you get your flu shot, request the flu shot — not the nasal spray vaccine. The flu shot is made from an inactivated virus, so it's safe for both mother and baby during any stage of pregnancy. The nasal spray vaccine is made from a live virus, which makes it less appropriate during pregnancy or while you're trying to conceive.

If you're allergic to eggs, check with your doctor before receiving a flu shot. The flu vaccine contains tiny amounts of egg protein. If you have an egg allergy or sensitivity, you'll likely be able to receive a flu shot — but you might need to take special precautions, such as waiting in the doctor's office for at least 30 minutes after vaccination in case of a reaction. There's also a flu vaccine that doesn't contain egg protein, approved for use in adults age 18 and older. Also check with your doctor if you had a severe reaction to a previous flu vaccine.

Oct. 16, 2014