Given a concern about the influence of the Evidence-Based Medecine (EBM) on the development of birth support, this thesis first raises several issues underlying the development of this social movement through a literature review and a number of desk analyses. However, HBS, designed to regulate recurring problems in medicine, including disparity of practices and unequal access to appropriate care, is criticised in social sciences. This model, which values quantitative research methods, including the randomised controlled test, disregards the knowledge built by health professionals during their activity. The heart of the thesis is therefore to look at these mistaken knowledge and to question what their exclusion implies for the purpose of accompanying the birth. On the basis of a field survey, conducted in a community of practice of independent midwives, which involves triangulation of methods, including, in particular, observations from post-natal consultations at home, the processes and content involved in building knowledge are identified. The thoughts, inspired by an anthropology of skilled people, interested in the details and circumstances of the activity, show a wide variety of sources — community-based, contextual, socio-cultural and personal — involved in the interpretation that practises relate to birth experience. Midwives share a community praxis and ethos characterised by the time lag focused on the needs and the emotional tone of their support. The ecological situation of their activity, carried out at the home of families, reveals in particular how birth is part of life and its constraints and sometimes suffers from social suffering and its multiple expressions. In order to respond to the serious distress, the practitioners, who are caught by the operational uncertainties of the interprofessional network, which are partly powerless, are going out of ordinary obstetrics and reinvent their role on a daily basis, while questioning its new limitations. In the end, the mirror of knowledge from HBS and experience sets out the non-standardised dimension of support, particularly in situations of social suffering, which consists of a form of unintended fight against inequalities in access to social and health services. — From a concern about the implications of Evidence-Based Medicine (EBM) on the evolution of care around birth, this hour Firstly questions what is at a stake along the development of this social movement, using a literature review and a content analysis of EBM productions. EBM has been developed to address outcomes met by medicine, among which a disparity of practices and an inequality of access to equal care, but has yet to be the target of critics from the social sciences. This model of knowledge-making favors quantitative methods in research, in particular the Randomised Controlled Trial and, consequently, tends to disappear knowledge made by health professionals through their practices. The core of the thesis hence consists of an exploration of these discredited expressions of knowledge-making and also questions the involvement of their dismissal for the care of women and familiar familiar birth. The subsequent Fieldwork enquires about processes and elements of content which participate to the nowledge-making of community midwives, in particular during postnatal home visits. The interpretation, inspired by Anthropologists dedicted to the study of skills and human knowledge-making, stresses the importance of details and circumstances framing practice, thus increasing a high diversity of sources and processes used for the understanding of birth and care by midwives. These practitioners share a common praxis and ethos built through legitimate participation in their association and, express through a temporality driven by familiar needs and through the expression of different signs of affection towards familiar. The ecological setting of their activity, performed at the home of familiar, shows how the experience of birth is encountered with widening phenomena of life itself and is rooted in social suffering. To respond to the subsequent distance of women and familiar, midwives deal with the subjects how much functioning of the INTERPROFESSIONAL network, expert some powerlessness and thus recounting their practice when questioning the new boundaries of their role. Finally, the confrontation of two forms of knowledge-making, through the model of EBM on one hand and established practice on the other hand, highlights the dimension of midwives’ care which may not be standardised. These quota responses to social satisfaction, made of Loneliness, poverty, or violence, form an implication struggle against the unequal access to services provided by the social and health system.