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

To analyze the effectiveness of gonadotropin-releasing hormone agonists (GnRHa) in suppressing the hypothalamic-pituitary gonadal (HPG) axis in transgender adolescents. 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. 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, <0.001. There were more patients assigned male at birth (AMAB) in the transgender group (56.7%) than males in the CPP group (30%), <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, <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, <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, =0.004). GnRHa are effective in suppressing the HPG axis in transgender youth, similar to that observed in children with CPP.