December 31st, 2009 
Delayed treatment of suspected influenza A (H1N1) illness among pregnant women may result in a four-fold risk of intensive care admission or death, according to results of a recent study.
Regardless of rapid antigen test results, prompt evaluation and antiviral treatment should be considered for pregnant or postpartum women displaying influenza A (H1N1)-like symptoms, according to researchers from the California Department of Public Health.
The study was a review of records for women of reproductive age who had been hospitalized or died from influenza A (H1N1) between April 23 and August 11, 2009.
The study involved 94 pregnant women, 137 non-pregnant women and 8 postpartum women who had delivered <2 weeks prior. False negative results for rapid antigen tests were observed in 38% of patients.
Among 94 pregnant women, 95% were in the second or third trimester. Risk factors for complications from influenza other than pregnancy were observed in 32 of 93 (34%) of those pregnant women.
Early antiviral treatment was defined as treatment <2 days after the onset of symptoms. Pregnant women treated later than this had an RR of 4.3 for admission to an ICU or death.
Intensive care was required for 18 pregnant women and four postpartum women (total, 22 of 102 [22%]). There were eight deaths (8%).
Of six deliveries which took place in the ICU, four were emergency cesarean deliveries.
The specific mortality ratio associated with influenza A (H1N1), which the researchers defined as the number of maternal deaths per 100,000, was 4.3.
