Endocrine Abstracts

An increasing number of transgender adolescents seeks medical care. After careful assessment and in the absence of contraindications, adolescents who have entered puberty, wish treatment and can provide informed consent can be treated with a GnRH analogue (GnRHa). This prevents further development of secondary sex characteristics incongruent with gender identity and provides the adolescent time to consider the option to undergo further gender affirming treatment. Studies on the efficacy and safety of GnRHa treatment will be reviewed. Adolescents who received mental health support plus GnRHa treatment were found to have improved global psychological functioning, reduced or stable emotional and behavioural problems, and reduced suicidality. GnRHa treatment effectively stops progression of breast development and menstrual bleeding in transboys. Those who start treatment in early puberty are less likely to request a mastectomy and, when operated, require less invasive surgery than those who start treatment later on. In transgirls, GnRHa treatment decreases testicular volume and prevents further virilization. However, the smaller size of penis and scrotum resulting from starting treatment in early puberty may affect later surgical options; for instance, penile inversion vaginoplasty may not be possible. The most commonly reported side effects of GnRHa treatment are mild headache and hot flushes. Serious adverse events are rare, but further data are needed on long-term safety. Height SDS decreases and so do bone mineral density z-scores. The great majority of adolescents choose to subsequently start gender affirming hormone treatment. Testosterone and estradiol then stimulate growth and bone mineral accrual, but limited data are available on adult height and bone mass. Another important issue is fertility, which may be compromised in those who choose to undergo further gender affirming treatment. Therefore, options for fertility preservation need to be discussed prior to the start of treatment.