Researchers from the CDC and the California Department of Public Health examined all H1N1-related hospitalizations among California women who were pregnant or had just given birth in the early months of the H1N1 pandemic.
The analysis revealed that only about half of the women received antiviral treatment within 48 hours of becoming ill.
Compared to pregnant women who received early treatment(given within 48 hours after the onset of symptoms),women treated later were four times more likely to die or require treatment in intensive care units (ICUs).
H1N1 Deaths: Treatment Delays Common
Of the 94 pregnant and eight postpartum California women hospitalized with H1N1 flu between April 23 and Aug. 11 of this year, 22 were treated in ICUs, 16 were put on ventilators, and eight died.
The CDC recommends starting antiviral treatment in pregnant women with suspected or confirmed H1N1 influenza within 48 hours of the onset of symptoms.
Five of the eight deaths occurred in women whose antiviral treatment began after this time.
In some cases, women did not seek treatment until after this time and in others the delays by health care providers in initiating treatment were to blame.
Eight of the 22 women who required ICU treatment were otherwise healthy, and 14 had medical conditions.
The analysis appears in the current issue of the New England Journal of Medicine.
CDC: Rapid Tests Not Reliable
Although tests that identify H1N1 influenza within 15 minutes are available, these rapid tests are not very reliable and could have contributed to treatment delays in this group of patients, the researchers concluded.
About 38% of patients with the flu had tested negatively (false negative results); less than 30% of patients with false negative results received antiviral treatment within 48 hours of symptom onset.
The CDC recently issued a health advisory alerting doctors on concerns about reliability of the rapid tests, making it clear that decisions about whether to start antiviral treatment should not be made based on their findings.
Seasonal influenza is a rare cause of death in pregnant women and new mothers, but this is not true of H1N1 influenza.
The researchers conclude that the 2009 H1N1 pandemic has the potential to increase rates of childbirth-related deaths in the U.S.
The report also highlighted the fact that new mothers are also at significant risk.
All eight of the new moms hospitalized for H1N1-related illness in the analysis became ill within two weeks of delivery. Half required ICU treatment and two died.