In this essay, I call on scientific persona and autobiographical discourse theory to examine Dr. Sara Josephine Baker’s 1939 autobiography Fighting for Life. Through this framework, I consider how Baker and other U.S. women health professionals conceived of individual identity and collective persona during the early twentieth century. Baker helped to revolutionise well-baby and well-child care in the U.S., and in Fighting for Life, she relates the genesis and evolution of her pathbreaking work. Like her contemporaries, Baker was engaged in the research, practice, teaching, and administration of medicine and public health. Presently, scientific persona has been theorized as a conglomerate of dispositions, practices, and characteristics that are associated with scholar-practitioners of the human and natural sciences; it therefore offers a novel lens for the individual and collective fashioning of women health professionals like Baker whose work traversed disciplines and institutions. By considering how Fighting for Life, as autobiography, facilitates Baker’s conception of self and persona, I show that Baker adopts prevailing personae for women health professionals as well as women working in other fields. At the same time, she also emphasizes why and how these models transform in actual practice. Thus, scientific personae tend to emerge as subtle variations of previous forms, but Baker’s autobiography also bears witness to the rise of new personae for women health professionals, as demonstrated by her radical reconfiguration of expert knowledge and scientific motherhood.