Effectiveness of Puberty Suppression with Gonadotropin-Releasing Hormone Agonists in Transgender Youth

Purpose: To analyze the effectiveness of gonadotropin-releasing hormone agonists (GnRHa) in suppressing the hypothalamic-pituitary gonadal (HPG) axis in transgender adolescents. Methods: Retrospective review of electronic medical records of transgender youth and children with central precocious puberty (CPP) treated with GnRHa. Blood levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, and/or estradiol at baseline and during treatment were compared between groups. Results: Data from 30 transgender and 30 patients with CPP were analyzed. Transgender patients were older with a mean age of 13.0±2.1 years versus 7.7±2.3 years in the CPP group, p<0.001. There were more patients assigned male at birth (AMAB) in the transgender group (56.7%) than males in the CPP group (30%), p<0.001. The transgender group had more patients with advanced puberty with 56% of patients having a Tanner stage of IV-V, versus none in the CPP group, p<0.01. GnRHa treatment resulted in LH, FSH, and testosterone levels that were similar in males with CPP versus transgender patients AMAB; suppression of LH and FSH levels was similar in females with CPP versus transgender patients assigned female at birth, but estradiol levels were higher in the latter (1.8±1.8 pg/mL vs. 9.4±9.7 pg/mL, respectively, p<0.001). FSH levels were lower in the transgender group treated with histrelin (0.8±0.8 mIU/mL vs. 1.9±1.2 mIU/mL in the leuprolide group, p=0.004). Conclusions: GnRHa are effective in suppressing the HPG axis in transgender youth, similar to that observed in children with CPP.