Abstract This paper presents the theory of French neurophysiologist Michel Jouvet that REM dreaming sleep acts as a genetic programming mechanism for the brain in utero. In addition the French neurobiologist Jean-Didier Vincent in his book Biology of Passions provides a great deal of research material concerning the development of the fetus as a desiring subject. This material is presented in support of the general theory of desire principally developed by French psychoanalysts Françoise Dolto and Jacques Lacan. It is shown that at the time of birth the fetus has already developed a desiring attachment to the conditions in the womb and that the act of being born does represent a rupture to its established desiring patterns thus reinforcing and explaining all the theory that has emerged concerning the trauma of birth.