Influenza infection and vaccination in pregnant women.

Evidence from previous influenza pandemics, epidemic seasonal influenza and, most recently, pandemic influenza A (H1N1) demonstrates that pregnant women and their offspring are at an increased risk for influenza-related complications. Influenza infections in pregnancy have been associated with adverse maternal and neonatal outcomes, including preterm labor and delivery, respiratory hospitalization, pneumonia, adult respiratory distress syndrome, overwhelming sepsis and death. The influenza vaccine has been repeatedly demonstrated to be both safe and effective in pregnant women and the potential for passive transfer of protective antibodies to the neonate adds to the cumulative benefits of maternal influenza immunization. Despite the potential benefit of this vaccine during pregnancy, low vaccination rates in both the USA and in other industrialized countries have been disconcerting.