An error that medicine has long shared is to attribute to a desire or an effect of the mother’s imagination during gestation, the deformities, growths or spots that a child bears at birth. The imagination would be capable of imprinting external modifications on a matter and would have an impact on the perceptions and sensory development of the fetus. Returning briefly to the genealogy and posterity of the topos, this article focuses on the successes and refutations of the Malebranchist paradigm (...) in the 18th century, through a corpus of medical popularization texts where the debates oppose the supporters of the imagination for whom emotion alters the organs of the fetus and the detractors of this thesis who only see it as prejudice. Mechanistic systems had in common that they avoided the soul to explain life. Although each era has its hermeneutic system of representations, and that medicine—closely dependent on the philosophical and moral conceptions of its time—is also a cultural production, it is nevertheless not uninteresting to question on the fortune of a motive and the scientific topicality of the question. What does the baby perceive in utero? Does he feel his mother’s pain? If so, what is the biological impact? To what extent can the maternal imagination and experience mark the child’s body? Informed by functional imaging technologies, recent research returns to the symbiotic link of mother-fetus interactions. Convergences appear between this 18th century and our 21st century. In no case did we want to contrast today’s scientists who are firmly in touch with reality and their predecessors who are prey to imagination. Science, whatever the era, always feeds on imagination. (shrink)