International audienceThe article argues against the common notion ofdisciplinary medical traditions, i.e. Obstetrics, asmacro-structures that quite unilinearily structure thepractices associated with the discipline. It shows that the various existences of Obstetrics, their relations with practices and vice versa, the entities these obstetrical practices render present and related, and the ways they are connected to experiences, are more complex than the unilinear model suggests. What allows participants to go from one topos to another – from Obstetrics to practice, from practice to politics, from politics to experience – is not self-evidently induced by Obstetrics, but needs to be studied as a surprising range of passages that connect (or don't). Techniques and devices to supervise the delivery, to render present the fetus during pregnancy, and to monitoring birth, are described in order to show that such techniques acquire different roles in connecting and creating Obstetrics as a system andobstetrical practices
