In the late 1920s, the American obstetrician Joseph DeLee brought the motion-picture camera into the birth room. Following that era's trend of adapting industrial efficiency practices for medical environments, DeLee's films give spectacular and unexpected expression to the engineering concept of 'streamlining'. Accomplishing what more tangible obstetric streamlining practices had failed to, DeLee's cameras, and his post-production manipulation, shifted birth from messy and dangerous to rationalized, efficient, death-defying. This was film as an active and effective medical tool. Years later, the documentarian Pare Lorentz produced and wrote his own birth film, The Fight for Life (1940). The documentary subject of the film was DeLee himself, and the film was set in his hospitals, on the same maternity 'sets' that had once showcased film's remarkable streamlining capacity to give and keep life. Yet relatively little of DeLee was retained in the film's content, resulting in a showdown that, by way of contrast, further articulated DeLee's understanding of film's medical powers and, in so doing, hinted at a more dynamic moment in the history of medicine while speaking also to the process by which that understanding ceased to be historically legible.