Pregnant women look for information on internet forums and share their experiences, even though the subject can be sensitive when it involves opiate maintenance treatments for instance. Their free use of this source of information enables researchers to know the experiences about the Subutex (high-dose buprenorphine) use in pregnancy of the women they would not normally have the opportunity of questioning: young women, pregnant or mothers, using internet, living with a partner, working, using an opiate substitution treatment, mostly prescribed by their GPs’.The analysis of the contents of these messages, realized by a thematic tree construction, shows five categories of interventions from the participating people. First, we identified their opinions and representations about Subutex in general and in the particular context of pregnancy. Secondly, we examined their shared knowledge on subjects about which they deplore the lack of information. Thirdly, they had more technical conversations, on how to stop Subutex before the end of pregnancy or on at least how to decrease the doses. The fourth point is that fear and guilty about Subutex intakes during pregnancy carry out an ideal of abstinence, leading women to flout medical advice when faced with the necessity to continue or even to increase the doses. Finally, a closer inspection of the children’s future, the newborn withdrawal and maternal lactation, in the context of this treatment, complete this spectrum.