Association of Gonadotropin-Releasing Hormone Analogue Use With Subsequent Use of Gender-Affirming Hormones Among Transgender Adolescents.

Importance: Gonadotropin-releasing hormone analogue (GnRHa) use during puberty improves mental health among transgender and gender-diverse (TGD) adolescents. In previous studies, most (96.5%-98.1%) TGD adolescents who started GnRHa subsequently started gender-affirming hormones (GAH), raising concerns that GnRHa use promotes later use of GAH. Objective: To determine whether GnRHa use among TGD adolescents is associated with increased subsequent GAH use. Design, Setting, and Participants: This is a retrospective cohort study of administrative records collected between 2009 and 2018. The current analysis was completed in August 2022. Participants were enrolled in the US Military Healthcare System (MHS) with an initial TGD-related encounter occurring between ages 10 and 17 years. Exposures: GnRHa use. Main Outcomes and Measures: Initiation of GAH. Results: The 434 patients were a mean (SD) of 15.4 (1.6) years old at the time of their first TGD-related encounter; 312 (71.9%) were assigned female at birth, and 300 (69.1%) had an enlisted insurance sponsor. GnRHa use was more common among patients who were assigned male at birth (28 patients [23.0%]) than those assigned female (42 patients [13.5%]), but GAH use was not. Socioeconomic status was not associated with GnRHa or GAH use. Compared with older patients (aged 14-17 years), those who were younger (aged 10-13 years) at the time of the initial TGD-related encounter had a higher rate of GnRHa use (32 patients [57.1%] vs 38 patients [10.1%]) and a longer median time to starting GAH. The median interval from the date of the initial encounter to starting GAH decreased over time, from 2.3 years (95% CI, 1.7-2.8 years) between October 2009 and December 2014 to 0.6 years (95% CI, 0.5-0.6 years) between September 2016 and April 2018. Patients who were prescribed GnRHa had a longer median time to starting GAH (1.8 years; 95% CI, 1.1-2.4 years) than patients who were not (1.0 years; 95% CI, 0.8-1.2 years) and were less likely to start GAH during the 6 years after their first TGD-related encounter (hazard ratio, 0.52; 95% CI, 0.37-0.71). Among 54 younger (aged 10-13 years) patients who were not eligible to start GAH at their first encounter, GnRHa use was associated with a longer median time to starting GAH, but age at the first TGD-related visit was not. Conclusions and Relevance: In this cohort study of TGD adolescents, GnRHa use was not associated with increased subsequent GAH use. These findings suggest that clinicians can offer the benefits of GnRHa treatment without concern for increasing rates of future GAH use.