The study describes the complex work of rielaboration of pre- oedipian and oedipian fantasies which is necessary to assume the parental role and underlines how some problematics of filiation can hamper this work and give rise to psychogenic infertilities and perinatal sychopathologies. In this perspective the study points and illustrates, by exposing a clinical case, the risks connected to the unconscious use of procreation medicalisation for defensive aims, that is the risk to deny or to bypass some problematics of filiation that in this way remain inelaborated and can have new kind of expression in perinatal psychopathologies.