1. Epidemiology of seasonal influenza infection in pregnant women and its impact on birth outcomes.
- Author
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Regan, A, Moore, H, Sullivan, S, DE Klerk, N, and Effler, P
- Subjects
Epidemiology ,infant health ,influenza A virus ,influenza B virus ,pregnant women ,Adult ,Cohort Studies ,Female ,Humans ,Influenza A virus ,Influenza ,Human ,Pregnancy ,Pregnancy Complications ,Infectious ,Retrospective Studies ,Seasons ,Western Australia ,Young Adult - Abstract
Seasonal influenza can cause significant morbidity in pregnant women. Much of the existing epidemiological evidence on influenza during pregnancy has focused on the 2009 A/H1N1 pandemic. To measure the epidemiological characteristics of seasonal influenza infection among pregnant women and the impact on infant health, a cohort of 86 779 pregnancies during the influenza season (2012-2014) was established using probabilistic linkage of notifiable infectious disease, hospital admission, and birth information. A total of 192 laboratory-confirmed influenza infections were identified (2·2 per 1000 pregnancies), 14·6% of which were admitted to hospital. There was no difference in the proportion of infections admitted to hospital by trimester or subtype of infection. Influenza B infections were more likely to occur in second trimester compared with influenza A/H3N2 and influenza A/H1N1 infections (41·3%, 23·6%, and 33·3%, respectively), and on average, infants born to women with influenza B during pregnancy had 4·0% (95% CI 0·3-7·6%) lower birth weight relative to optimal compared with infants born to uninfected women (P = 0·03). Results from this linked population-based study suggest that there are differences in maternal infection by virus type and subtype and support the provision of seasonal influenza vaccine to pregnant women.
- Published
- 2017