Increased morbidity and mortality in pregnant women were reported following three major historical influenza pandemics. To prevent influenza infection during pregnancy, the Centers for Disease Control (CDC) and the American College of Obstetricians and Gynecologists (ACOG) recommend that all pregnant women and those intending to get pregnant during the influenza season be vaccinated. In 2004, they advised expanding vaccination guidelines from the second and third trimester to all three trimesters. We evaluated the safety of influenza vaccination during pregnancy in 182 subjects from 2007-2009. No adverse events were seen in pregnancy or fetal medical condition regardless of the pregnancy stage at which vaccine was administered.