Pragmatic approach to intersex, including genital ambiguity, in the newborn

The evaluation and management of a newborn with ambiguous genitalia must be undertaken as quickly as possible and with great sensitivity for the child's family. Where possible, a comprehensive team approach with a pediatric urologist, endocrinologist, geneticist, neonatologist, and child psychiatrist/psychologist should work closely with the family to establish the diagnosis and determine gender. Although the preferred gender assignment is not always clear, a thorough examination of endocrine function, karyotype, and potential for fertility should guide the determination. While some disorders of sex development (DSD) sex assignments are relatively straightforward, those with more advanced genital ambiguity and unclear gonadal function represent a major challenge. A child's phenotypic sex results from the differentiation of internal ducts and external genitalia under the influence of hormones and transcription factors. Any discordance among these processes results in ambiguous genitalia or DSD. Currently, the main categories of DSD are 46,XX DSD, 46,XY DSD, sex chromosome DSD, ovotesticular DSD, and 46,XX testicular DSD. Priority is given to rule out more immediate life-threatening disorders like salt wasting CAH. Many centers in the United States lack the comprehensive "team members" and not all conditions necessitate this team approach. This article aims to provide guidance for initial workup and identify the specific conditions for which expert guidance is needed.