ESPE Yearbook of Paediatric Endocrinology

Brief summary: This paper investigated the effect of pubertal suppression with GnRHa and gender affirming treatment with testosterone on the growth and final height of transgender boys. They found no negative effects, and even possibly a slight boost to adult height in comparison with target and predicted heights for birth-registered sex.

One of the concerning features of transgender males is being able to identify with their cisgender peers in stature. In the ESPE Yearbook 2022 we reported a paper from the same authors finding that the adult height of transgender girls in relation to their birth-registered sex was not affected by hormonal interventions (1). This study reports adult height outcomes in 146 transgender boys who received GnRHa then testosterone treatment. The younger ones (bone age below 14 years at start (n=61) had an adult height SD score similar to the baseline and that adult height was greater than mid-parental height and the predicted adult height at the start of treatment. Further sub-analysis showed that those with a younger bone age when treatment was started had adult heights which were significantly above their predicted adult height. Not only are these findings reassuring, but they also provide insights into the control of growth in healthy adolescents and how hormonal manipulations can change the ultimate growth trajectory by manipulating puberty, in this case to achieve a desired endpoint.

Reference: 1. Boogers LS, Wiepjes CM, Klink DT, Hellinga I, van Trotsenburg ASP, den Heijer M, Hannema SE. Transgender Girls Grow Tall: Adult Height Is Unaffected by GnRH Analogue and Estradiol Treatment. J Clin Endocrinol Metab. 2022 Aug 18;107(9):e3805–e3815. doi: 10.1210/clinem/dgac349. PMID: 35666195; PMCID:PMC9387709.