A study has found that pregnant women had a disproportionately higher risk of death due to 2009 influenza A(H1N1) in the United States. The study published in JAMA also found that early antiviral treatment appeared to be associated with fewer admissions to an ICU and fewer deaths.
Researchers analyzed data on influenza cases of pregnant women with symptom onset from April through December 2009. During the initial period of data collection (April-August 2009), a total of 788 cases of influenza A(H1N1) among pregnant women were reported. Among those, 30 died (5% of all reported 2009 influenza A[H1N1] deaths in this period). Among 509 hospitalized women, 115 (22.6%) were admitted to an ICU.
Data collected of cases with symptom onset through December 31, 2009 showed an additional 165 women for a total of 280 who were admitted to ICUs, 56 of whom died. Among the deaths, 4 occurred in the first trimester (7.1%), 15 in the second (26.8%), and 36 in the third (64.3%).
Pregnant women with treatment more than 4 days after symptom onset were six times more likely to be admitted to an ICU (56.9% vs. 9.4%) than those treated within 2 days after symptom onset.
“Our analysis supports 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 study authors write.