Teens in transition: Efficacy and safety of pubertal suppression and induction in adolescents with gender dysphoria

In this thesis, we analysed the efficacy and safety of PS and GAHT in transgender and gender diverse (TGD) adolescents by describing its impact on various components of pubertal development such as body composition, breast development, skeletal dimensions, and bone mineral density (BMD). This thesis enhances our understanding of the efficacy of PS and GAHT in TGD adolescents by demonstrating their influence on pubertal development, extending beyond the primary aim of preventing secondary sex characteristics of the assigned sex and promoting those of the affirmed gender. Early initiation of PS results in physical characteristics, such as pelvic and shoulder dimensions, that align more closely with the affirmed gender, underscoring the irreversible effects of exposure to endogenous sex hormones during puberty. However, this does not apply to all outcomes, such as breast development. This suggests that additional factors, including genetic differences, pre- or early postnatal sex hormone exposure, or the absence of progesterone in feminising GAHT, also play a significant role. This research provides valuable insights for the ongoing discussions surrounding the safety of PS and GAHT in TGD adolescents, particularly concerning BMD in transfeminine adolescents. By examining the effects of different hormone doses on BMD and exploring its potential natural time course, this thesis offers new perspectives on these important safety considerations and provides concrete recommendations to enhance bone health in transfeminine adolescents. Beyond advancing our understanding of the efficacy and safety of PS and GAHT during pubertal development, the findings of this thesis are essential in optimizing treatment and counselling for TGD adolescents. Additionally, the establishment of the ENIGI Adolescents study has laid a solid foundation for addressing remaining questions, paving the way for future advancements in the field.