Evaluation of the newborn with developmental anomalies of the external genitalia

The newborn with abnormal genital development presents a difficult diagnostic and treatment challenge for the primary care pediatrician. It is important that a definitive diagnosis be determined as quickly as possible so that an appropriate treatment plan can be established to minimize medical, psychological, and social complications. The purpose of this review is to identify which newborns among those with abnormal genital development need to be screened for intersexuality, to outline the investigations necessary, and to suggest indications for referral to a center with experience in the diagnosis and management of these disorders. An outline is also presented of the embryology of the external genitalia indicating where errors can arise to provide a framework for pediatricians to use when counseling families. Although the focus of this review is on newborns with what has been termed 'ambiguous genitalia,' it should be recognized that most genital abnormalities in newborns do not result in an ambiguous appearance. These anomalies include hypospadias, in which the genitalia are clearly malformed, although the sex is unquestionably male.