For the treatment of breast cancer, modifications of decision making related to pregnancy could be assessed through three questions. Why a decision had been chosen? In that case, the hypothesis is that decisions are based on the expected utility. The theory assumes weighting and computation of complete possibilities with their associated probabilities and values. However values exhibits a wide inter-individual variation range. Therefore the predictability of choice based on this model is indeed very low. Furthermore it is likely that the willingness of pregnancy after breast cancer contains besides classic constituents of appeals of motherhood, a specific meaning of recovery both of health and femininity. The second question: who is in charge of the decision? And under the paradigm of autonomy, women' decision is, merely by itself, the right decision. The last question is how? For some situations for which foreseeing is quiet complex, the value of the process in itself is increased and could help the end-oriented or self-determined decision. Casuistic analysis could therefore improve women' decisions. The issue is not only about decision but also related to patient-physician relationship, about an issue that is not only a biomedical problem.