This definition of the term "live birth" was created by the World Health Organization in 1950 and is chiefly used for public health and statistical purposes. Whether the birth is vaginal or by Caesarean section, and whether the neonate is ultimately viable, is not relevant to this statistical definition. However, the term "live birth" was in common use long before 1950.
In the United States, the term "born alive" is defined by federal statute.