Continuation of gender-affirming hormones in transgender people starting puberty suppression in adolescence: a cohort study in the Netherlands

Background: In the Netherlands, treatment with puberty suppression is available to transgender adolescents younger than age 18 years. When gender dysphoria persists testosterone or oestradiol can be added as gender-affirming hormones in young people who go on to transition. We investigated the proportion of people who continued gender-affirming hormone treatment at follow-up after having started puberty suppression and gender-affirming hormone treatment in adolescence. Methods: In this cohort study, we used data from the Amsterdam Cohort of Gender dysphoria (ACOG), which included people who visited the gender identity clinic of the Amsterdam UMC, location Vrije Universiteit Medisch Centrum, Netherlands, for gender dysphoria. People with disorders of sex development were not included in the ACOG. We included people who started medical treatment in adolescence with a gonadotropin-releasing hormone agonist (GnRHa) to suppress puberty before the age of 18 years and used GnRHa for a minimum duration of 3 months before addition of gender-affirming hormones. We linked this data to a nationwide prescription registry supplied by Statistics Netherlands (Centraal Bureau voor de Statistiek) to check for a prescription for gender-affirming hormones at follow-up. The main outcome of this study was a prescription for gender-affirming hormones at the end of data collection (Dec 31, 2018). Data were analysed using Cox regression to identify possible determinants associated with a higher risk of stopping gender-affirming hormone treatment. Findings: 720 people were included, of whom 220 (31%) were assigned male at birth and 500 (69%) were assigned female at birth. At the start of GnRHa treatment, the median age was 14·1 (IQR 13·0–16·3) years for people assigned male at birth and 16·0 (14·1–16·9) years for people assigned female at birth. Median age at end of data collection was 20·2 (17·9–24·8) years for people assigned male at birth and 19·2 (17·8–22·0) years for those assigned female at birth. 704 (98%) people who had started gender-affirming medical treatment in adolescence continued to use gender-affirming hormones at follow-up. Age at first visit, year of first visit, age and puberty stage at start of GnRHa treatment, age at start of gender-affirming hormone treatment, year of start of gender-affirming hormone treatment, and gonadectomy were not associated with discontinuing gender-affirming hormones. Interpretation: Most participants who started gender-affirming hormones in adolescence continued this treatment into adulthood. The continuation of treatment is reassuring considering the worries that people who started treatment in adolescence might discontinue gender-affirming treatment. Funding: None

Transgender Girls Grow Tall: Adult Height Is Unaffected by GnRH Analogue and Estradiol Treatment

CONTEXT: Transgender adolescents can receive gonadotropin-releasing hormone analogues (GnRH) and gender-affirming hormone therapy (GAHT), but little is known about effects on growth and adult height. This is of interest since height differs between sexes and some transgender girls wish to limit their growth. OBJECTIVE: This work aims to investigate the effects of GnRHa and GAHT on growth, and the efficacy of growth-reductive treatment. METHODS: This retrospective cohort study took place at a specialized tertiary gender clinic. A total of 161 transgender girls were treated with GnRHa and estradiol at a regular dose (2 mg) or high growth-reductive doses of estradiol (6 mg) or ethinyl estradiol (EE, 100-200 µg). Main outcome measures included growth, adult height, and the difference from predicted adult height (PAH) and target height. RESULTS: Growth velocity and bone maturation decreased during GnRHa, but increased during GAHT. Adult height after regular-dose treatment was 180.4 ± 5.6 cm, which was 1.5 cm below PAH at the start GnRHa (95% CI, 0.2 cm to 2.7 cm), and close to target height (-1.1 cm; 95% CI, -2.5 cm to 0.3 cm). Compared to regular-dose treatment, high-dose estradiol and EE reduced adult height by 0.9 cm (95% CI, -0.9 cm to 2.8 cm) and 3.0 cm (95% CI, 0.2 cm to 5.8 cm), respectively. CONCLUSION: Growth decelerated during GnRHa and accelerated during GAHT. After regular-dose treatment, adult height was slightly lower than predicted at start of GnRHa, likely due to systematic overestimation of PAH as described in boys from the general population, but not significantly different from target height. High-dose EE resulted in greater reduction of adult height than high-dose estradiol, but this needs to be weighed against possible adverse effects

Just as tall on testosterone; a neutral to positive effect on adult height of GnRHa and testosterone in trans boys

CONTEXT: Growth is an important topic for many transgender boys. However, few studies have investigated the impact of puberty suppression (PS) and gender affirming hormone treatment (GAHT) on growth and adult height. OBJECTIVE: To evaluate the effect of PS and GAHT on growth and adult height. DESIGN: Retrospective cohort study. SETTING: Specialised gender identity clinic. PARTICIPANTS: 146 transgender boys treated with GnRH analogues and testosterone who reached adult height. MAIN OUTCOME MEASURES: Growth, bone age (BA), adult height, and difference between adult height and predicted adult height (PAH) and midparental height. RESULTS: In those with BA ≤14 year at start (n = 61), a decrease in growth velocity and bone maturation during PS was followed by an increase during GAHT. Adult height was 172.0 ± 6.9 cm; height SDS was similar to baseline (0.1, 95% CI -0.2 to 0.4). Adult height was 3.9 ± 6.0 cm above midparental height and 3.0 ± 3.6 cm above PAH at start of PS. A younger BA at start PS was associated with an adult height significantly further above PAH. CONCLUSION: During PS, growth decelerated followed by an acceleration during GAHT. Although adult height SDS was similar to baseline, adult height was taller than predicted based on BA at baseline, especially in those who started treatment at a younger BA. It is reassuring that PS and GAHT do not have a negative impact on adult height in transgender boys and might even lead to a slightly taller adult height, especially in those who start at a younger age