By means of qualitative methods (semi-structured interviews) and quantative ones, this article explores parental experiences, particularly traumatic ones, the quality of interactions and the representations of maternal attachment as well as the outcome of the premature child born under 34 weeks of gestation. At 6 and 18 months, the quality of mother/child interactions is not less good when the child presents a high perinatal risk or when the mother suffers a high level of stress. The exploration of interactive dyadic patterns reveals both a « coopératives » pattern, comparable to that of « at term » dyads, and a more problematical « controlling » pattern, in connection with the « distorted » representations of attachment which constitute a risk factor for the outcome of the child. These results underline the importance of maternal post traumatic stress in the event of a premature birth and the necessity for early therapeutic interventions.