ACOG committee opinion number 305, November 2004. Influenza vaccination and treatment during pregnancy.

Influenza vaccination is an essential element of prenatal care. The American College of Obstetricians and Gynecologists' Committee on Obstetric Practice supports the Centers for Disease Control and Prevention's expanded recommendation that women who will be pregnant during the influenza season (October through mid May) should be vaccinated. The ideal time to administer the vaccine is October and November; however, it is appropriate to vaccinate patients throughout the influenza season as long as the vaccine supply lasts. This intramuscular inactivated vaccine may be used in all 3 trimesters. Because of the unknown effects of influenza antiviral drugs on pregnant women and their fetuses, the Committee on Obstetric Practice recommends that these antiviral agents should be used during pregnancy only if the potential benefits justify the potential risks.