Answering to one of the objectives of the research, one searched to identify where to know if it supports the knowledge and the practical one of the traditional obstetrician. Which its epistemolgica base? To identify this question it was necessary to make a passage of the understanding concerning the values that nourish our culture and support scientific the thought current. Capra (1996) comes to contribute clarifying that the scientific revolution in centuries XVI and XVII, constituted a new vision of world, characterized for a reducionista understanding of the reality. Czeresnia (2009, P.

45) portraies the trend to the reduction, the precision and to the objetividade, where the events and the questions of the life pass to be transformed into projects calculated and demonstrated. In the requirement for the exactness of the things and the events what science does not obtain to apprehend or to prove it passes to be considered abnormal or pathological. Here if it perceives, as physiological events, as the pregnancy, the childbirth, the menstruation was throughout history, transformed into riots (SEIBERT 2005, p.248). For Borges (2008, P. 324) if it cannot abstract that a predominance of a hegemonic power of scientific knowing exists on other forms of practical organizations and, many times, submitted to the exclusion and the silenciamento, being recognized as rival cultures, that is, in the speeches on the scientific knowledge, the knowledge of the common sense is recognized in opposition, starting to understand that this has access only to a restricted world and that it does not have value stops beyond it. tml ‘>Steven P Rosenthal). (SAINTS 2002 apud BORGES, 2008, P. 324). The forms to take care of of the obstetricians, in accordance with Borges (2008) to the eyes of the rationality of science, are presented null and void, it does not have the necessary qualification and meet silenced and denied.