2009 pandemic influenza A (H1N1) in pregnant women requiring intensive care - New York City, 2009.

Pregnant women are at increased risk for severe illness and complications from infection with seasonal influenza and 2009 pandemic influenza A (H1N1). To characterize the severity of 2009 H1N1 infection in pregnant women, the New York City Department of Health and Mental Hygiene (DOHMH) conducted active and passive surveillance for cases of 2009 H1N1 infection in pregnant women requiring intensive care. This report summarizes the results of that surveillance, which found that, during 2009, 16 pregnant women and one who was postpartum were admitted to New York City intensive-care units (ICUs). Two women died. Of the 17 women, 12 had no recognized risk factors for severe influenza complications other than pregnancy. All 17 women received antiviral treatment with oseltamivir; however, treatment was initiated <or=2 days after symptom onset in only one woman and was begun >or=5 days after symptom onset in four women. Because initiation of antiviral treatment <or=2 days after onset is associated with better outcomes, pregnant women should be encouraged to seek medical care immediately if they develop influenza-like symptoms, and health-care providers should initiate empiric antiviral therapy for these women as soon as possible, even if >2 days after symptom onset. Health departments and health-care providers should educate pregnant and postpartum women regarding the risks posed by influenza and highlight the effectiveness and safety of influenza vaccination. Obstetricians and other health-care providers should offer influenza vaccination to their pregnant patients.