A practical approach to intersex in the newborn period.

Sexual determination is a complex process that occurs in an organized sequential manner. When chromosomal, gonadal, or phenotypic sex determination goes awry,intersexuality develops. Advances in molecular biology have made it easier to understand the various phenotypes that are encountered. It is easy to be overwhelmed when reviewing the testosterone synthesis pathway and the intersex differential diagnosis. This article presents a useful approach to the evaluation of the newborn with ambiguous genitalia.