Despite enormous advances in the understanding of the molecular mechanisms of sexual differentiation, the medical decisions made in patients with disorders of somatosexual differentiation are mostly lacking evidence-based principles. Recent critical discussions have focused on approaches to gender assignment in infants with ambiguous genitalia. These decisions must be based on the correct diagnosis to be able to predict the development during puberty and adulthood in the affected individual. Puberty in this process plays a pivotal role not only because of the physical changes induced by endogenous or supplementary sex steroids to enhance the sex of rearing, but it is also the time for sexual orientation and promotion of gender identity. In this review we focus not only on the molecular impact of sex steroid action, but also view current opinions and studies on the gender development of the intersex patient during puberty.
