Ambiguous genitalia in the newborn: an overview and teaching tool.

Ambiguous genitalia is a significant example of a disorder of sexual development, in which the external genitalia do not have the typical appearance of either sex. Although the birth of a child with ambiguous genitalia is rare, the emergent nature of the issue demands that healthcare providers have at least a familiarity with the underlying etiologies, the issues, and the initial approach to diagnosis and management. With numerous etiologies, potential difficulties with reaching a diagnosis, and many challenges with immediate and long-term care, the topic of ambiguous genitalia can be daunting. We provide a review of basic embryology, as well as a classification system for understanding the various etiological causes of ambiguous genitalia. The important clinical aspects of diagnosis and management are also highlighted, and a teaching tool has been included to help the reader (or their learners) to solidify information presented. Our overall goal is to provide practical information on ambiguous genitalia and allow the clinician to apply this information to clinically relevant scenarios.