CDC Report Confirms Pregnant Women at Increased Risk for H1N1 Death
Pregnant women infected with the 2009 influenza A (H1N1) virus are at increased risk for death compared with others, but treatment within 2 days of symptom onset decreased this risk, according to a study by the Centers for Disease Control and Prevention (CDC), published in the April 21 issue of the Journal of the American Medical Association.
Alicia M. Siston, PhD, and colleagues from the Pandemic H1N1 Influenza in Pregnancy Working Group analyzed data reported to the CDC on pregnant women from April 2009 through December 2009.
Of the 788 pregnant women with symptom onset occurring from April 2009 to August 2009, 30 died, representing 5% of all deaths from H1N1 occurring during this time. In addition, 509 pregnant women were hospitalized; among those, 22.6% were admitted to an intensive care unit (ICU).
Early treatment improved outcomes among pregnant women. Of those treated more than 4 days after symptom onset, 56.9% were admitted to an ICU compared with only 9.4% of those treated within 2 days of symptom onset (relative risk [RR], 6.0; 95% confidence interval [CI], 3.5 - 10.6). Only 1 patient treated within 2 days died compared with 29 patients treated more than 4 days after symptom onset.
Ongoing surveillance of pregnant women continued until December 31, 2009, and an additional 165 women admitted to ICUs were identified, for a total of 280 women; among those women, there were 56 deaths.
"Pregnant women represent approximately 1% of the US population, yet they accounted for 5% of US deaths from 2009 influenza A(H1N1) reported to the CDC," the researchers write. These data are consistent with earlier studies showing pregnant women at higher risk for complications from H1N1, including serious illness and death. "Changes in the immune, cardiac, and respiratory systems are likely reasons that pregnant women are at increased risk for severe illness with influenza," the authors suggest.
According to the researchers, their findings support "current public health recommendations for pregnant women that include vaccination with 2009 influenza A(H1N1) monovalent vaccine and early treatment of women who present with possible 2009 influenza A(H1N1) with antiviral medications."
The authors have disclosed no relevant financial relationships.