Trends in influenza vaccine coverage in pregnant women, 2008 to 2012.

CONTEXT Pregnant women are at increased risk of severe influenza-related complications and hospitalizations and are a priority group for influenza vaccination. OBJECTIVE To examine coverage of seasonal and pandemic influenza A (H1N1) vaccines in pregnant women in a managed care setting, from 2008 to 2012. DESIGN Retrospective cohort study of 10,145 pregnant women. MAIN OUTCOME MEASURES H1N1 and seasonal influenza vaccination rates. RESULTS Seasonal influenza vaccine coverage increased from 38% to 63% between the 2008-2009 and 2010-2011 seasons, and then dropped to 61% in 2011-2012. Vaccine coverage was higher in women considered at high risk of influenza complications, increasing from 43% in 2008-2009 to 71% in 2010-2011, before decreasing to 69% in 2011-2012. H1N1 vaccine coverage was greater than seasonal influenza coverage in 2009-2010 in the overall pregnant population (61% vs 53%) and in the high-risk group (64% vs 59%). We observed statistically significant differences in vaccination rates by trimester, gravidity, maternal age, and race/ethnicity. CONCLUSIONS Vaccination rates increased significantly from 2008 to 2011, then dropped slightly in 2011-2012. Continued efforts are needed to ensure adequate vaccination coverage in this high-risk population.