BACKGROUND AND PURPOSE:

• Holstein et al. (Annals of Internal Medicine, 2021) describe characteristics and outcomes of hospitalized pregnant women with influenza

METHODS:

• Cross-sectional study
  • Data derived from FluSurv-NET
  • Large, multicenter, CDC–sponsored network
  • Represents about 9% of the U.S. population
• Population
  • Women 15 to 44 years
  • Hospitalized with laboratory-confirmed influenza
• Exposures
  • Pregnancy status
  • Influenza A subtype
• Study design
  • Flu seasons assessed were 2010–2011 through 2018–2019 influenza seasons
  • Clinical characteristics, interventions, and in-hospital maternal and fetal outcomes were obtained through medical chart abstraction
  • Multivariable logistic regression was used to evaluate the association between influenza A subtype and outcomes
• Primary outcomes
  • Severe maternal influenza-associated outcomes including
    • ICU admission
    • Mechanical ventilation
    • Extracorporeal membrane oxygenation (ECMO)
    • In-hospital death

RESULTS:

• 9652 women hospitalized with influenza
  • Pregnant: 27.9%
• Characteristics of pregnant women hospitalized with influenza
  • Median age: 28 years
  • Third trimester: 62%
  • Had at least 1 underlying condition: 42%
  • Vaccinated against influenza: 32%
  • Received antivirals: 88%
• Influenza outcomes
  • Required ICU admission: 5%
  • Required mechanical ventilation: 2%
  • ECMO: 0.3%
  • Deaths: 0.3%
• Pregnant women with influenza A H1N1 were more likely to have severe outcomes than those with influenza A H3N2
  • Adjusted risk ratio 1.9 (95% CI, 1.3 to 2.8)
• Most women were still pregnant at discharge: 71%
• Pregnancy outcomes of those who were no longer pregnant at discharge
  • Live birth: 96%
  • Fetal loss: 3%

CONCLUSION:

• Over the last 9 influenza seasons (2010 through 2019) in the US, a third of reproductive-aged women hospitalized with influenza were pregnant and symptomatic at the time of admission
• Severe maternal outcomes were more likely in women with influenza A H1N1
• The authors state

Considering that approximately 5% of U.S. women of reproductive age are pregnant at any given time, our study contributes to the evidence showing that pregnant women are disproportionately burdened by influenza-associated hospitalization

Pregnant women remain a high-priority target group for vaccination

Learn More – Primary Sources:

Characteristics and Outcomes of Hospitalized Pregnant Women With Influenza, 2010 to 2019

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