The author demonstrates with the help of a case study how one can miss the complex subjectivity of a patient and potentially damage her, if the basis for therapeutic action consists in an understanding of informed consent reduced purely to conscious factors. In the context of a painful gynaecological infection the patient had been asked about her potential wish to have children. Until then this had not been a preoccupation of hers, but now having ‘a child’ seemed to epitomize to her a life without injustices, disadvantages, restrictions and so on. On one level she ‘sensed’ the illusionary character of this ‘solution’, while on another level she insisted on its concrete realization. The medical offer of IVF treatment, although formally in accordance with informed consent, did not take into account this split psychic situation and thus precipitated unforeseen complications.