Influenza and pregnant women: hospitalization burden, United States, 1998-2002.

Women in later stages of pregnancy are at increased risk for serious influenza-related morbidity; thus, universal influenza vaccination of pregnant women is recommended. However, vaccine uptake in the United States has been suboptimal. We previously described the burden of severe influenza-related morbidity during pregnancy in the United States by examining hospitalizations of pregnant women with respiratory illness during influenza season. Nondelivery hospitalizations with respiratory illness had significantly longer lengths of stay than those without respiratory illness. Hospitalization characteristics associated with greater likelihood of respiratory illness were the presence of a high-risk condition for which influenza vaccination is recommended, Medicaid/Medicare as primary expected payer, and hospitalization in a rural area. These findings may be explained by these women being at higher risk of influenza-related morbidity or reflect disparities in receipt of influenza immunization. Universal vaccination of pregnant women to decrease influenza-related morbidity should be encouraged.