Influenza vaccination in pregnancy: large study supports safety

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  • Results suggest influenza vaccination at any stage during pregnancy does not affect infant birthweight or gestational age, a finding supported by emerging international literature.

Why this matters

  • Few studies have reliably validated receipt of influenza vaccination, and therefore limited data are available for assessing adverse birth outcomes in relation to trimester of vaccination.

Study design

  • Nested retrospective cohort study of mother-infant pairs in the prospective, ongoing "FluMum" cohort study.
  • Primary outcomes were birthweight and gestational age at birth for live singleton infants.
  • Funding: National Health and Medical Research Council Project Grant.

Key results

  • Among 7126 women, 34% were vaccinated (14% in first trimester, 51% ...