This article focuses on Britain's 1917 National Baby Week and specifically how it played out in London. Pageantry and celebration were an important part of the event, and possibly a welcome distraction from the trials and horrors of war, and they were embraced by women of all social classes. But there was much more to it, as women who led the event seized the opportunity for political purposes, in what appeared to be an unthreatening environment of celebrating motherhood. Their goal was to promote the material wellbeing of, and state support for, women and children, and in this they were remarkably successful. Baby Week was also seized upon as an opportunity to showcase other welfare systems as a model for Britain, focusing in particular on New Zealand, with its free and comprehensive health service for infants. Rather than reflecting the eugenic and pronatalist concerns of the establishment, the event should be seen as a moment of politicisation of women arguing for cross-class social reform targeted at mothers.