During pregnancy you are at risk for complications from influenza, such as pneumonia. Studies done over 17 flu seasons have demonstrated that pregnant women in their third trimester were as likely to be hospitalized for lung or heart problems as women with serious, chronic medical conditions who were not pregnant. This risk seemed to increase later in pregnancy, particularly after about week 37. Pregnant women with asthma were particularly at risk.
The Centers for Disease Control and Prevention recommend that pregnant women get the flu shot. If you will be past 13 weeks in your pregnancy any time from late November through March, you should probably get the flu shot. As always, you should discuss this with your physician.
The flu shot is made from “inactivated” virus, and is considered safe during any stage of pregnancy. Few studies have been done regarding the effect of the flu shot on the fetus, but those that have been done do not indicate any increased risk for the fetus. Pregnant women should not use “FluMist” – a nasal spray version of the influenza vaccine – because it contains actual live influenza virus.