This large national cohort study followed-up pregnant women admitted to hospital and found to have laboratory-confirmed influenza A(H1N1) 2009 infection during the autumn-winter wave of the 2009 pandemic. The main objective was determining any adverse pregnancy outcomes attributable to the infection.

​Following an earlier consultation document issued in March 2011 the UK’s Secretary of State for Health, along with the UK’s developed administrations (N. Ireland, Scotland and Wales) published a new influenza pandemic strategy on 10 November.