When stillbirth registration became mandatory in England and Wales in 1926, it was not to amass statistics in the service of public health. Instead, it was part of broader anxieties that victims of infanticide were being disposed of under the guise of having been stillborn. But because it necessitated distinguishing between the living and the dead, the legislation that introduced stillbirth registration generated debate about the definition of life itself. This focused both on what counted as a sign of life and on questions about the viability of preterm infants. These contentious disputes had serious repercussions for the treatment of premature births well into the twentieth century. Significantly, they also underscore that what classifies a person as dead or alive is never self-evident. Instead, the state's authorized definition of life is under permanent negotiation as it is always mobilized in the service of particular regimes of power.