Abstract
The newborn infant with atypical genitalia presents a challenging clinical scenario and requires expert input. There have been appreciable advances in our knowledge of the underlying causes that may lead to a mere difference or a more serious disorder of sex development (DSD), the natural history of conditions, as well as the short and long-term complications of these conditions themselves, together with the clinical interventions that are associated with these conditions. With this information, the DSD expert can be more confident when discussing options with the parents of the newborn infant. By working within a multidisciplinary team, the expert should be able to support the family whilst individualising the management plan so that it is also cognizant of the shifts in societal attitudes and expectations around concepts of diversity and openness. It is, therefore, likely that the practice of assigning sex, especially in those cases where sex assignment is unclear on expert assessment, will continue to show temporal, social and geographical variations. It is imperative that clinical data for rare conditions such as these are collected in a standardized format and shared through a common registry so that any evidence that is used for future shifts in practice has a stronger foundation than that which is currently available.