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Trajectories of transgender adolescents referred for endocrine intervention in England
  1. Una Masic1,
  2. Gary Butler2,
  3. Paul Carruthers3,
  4. Polly Carmichael1
  1. 1 Gender Identity Development Service, Tavistock and Portman NHS Foundation Trust, London, UK
  2. 2 Department of Paediatrics and Adolescents, University College London Hospital, London, UK
  3. 3 Department of Endocrinology, Leeds Children's Hospital, Leeds, West Yorkshire, UK
  1. Correspondence to Dr Una Masic, Gender Identity Development Service, Tavistock and Portman NHS Foundation Trust, London, UK; umasic{at}


Objectives Some gender-diverse young people (YP) who experience clinically significant gender-related distress choose to pursue endocrine treatment alongside psychotherapeutic support to suppress pubertal development using gonadotropin-releasing hormone analogues (GnRHa), and then to acquire the secondary sex characteristics of their identified gender using gender affirming hormones (GAH). However, little is known about the demographics of transgender adolescents accessing paediatric endocrinology services while under the specialist Gender Identity Development Service (GIDS) in England.

Design Demographics of referrals from the GIDS to affiliated endocrinology clinics to start GnRHa or GAH between 2017 and 2019 (cohort 1), with further analysis of a subgroup of this cohort referred in 2017–2018 (cohort 2) were assessed.

Results 668 adolescents (227 assigned male at birth (AMAB) and 441 assigned female at birth (AFAB)) were referred to endocrinology from 2017 to 2019. The mean age of first GIDS appointment for cohort 1 was 14.2 (±2.1) years and mean age of referral to endocrinology postassessment was 15.4 (±1.6) years. Further detailed analysis of the trajectories was conducted in 439 YP in cohort 2 (154 AMAB; 285 AFAB). The most common pathway included a referral to access GnRHa (98.1%), followed by GAH when eligible (42%), and onward referral to adult services when appropriate (64%). The majority (54%) of all adolescents in cohort 2 had a pending or completed referral to adult services.

Conclusions This study highlights the trajectories adolescents may take when seeking endocrine treatments in child and adolescent clinical services and may be useful for guiding decisions for gender-diverse YP and planning service provision.

  • endocrinology
  • adolescent health
  • child health
  • child health services
  • child development

Data availability statement

No data are available. Owing to the sensitive nature of this patient data, and to ensure anonymity, data are not available to share.

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  • International evidence presenting the demographics and trajectories of gender-diverse young people accessing care allows for understanding around the differences between clinics in available care pathways

  • International evidence is used in considerations around future treatment options into adulthood for gender-diverse young people.


  • This is the first assessment of endocrine treatment trajectories of a cohort of gender-diverse adolescents attending the largest child gender service in Europe

  • The trajectories identified were predominantly consistent with identifying with a gender other than assigned gender, this suggests those pursuing treatment comprise a highly selective group whose identity is consistent with treatment.


  • Understanding pathways through GIDS allows for future comparisons with findings from other services around treatment decisions made by highly selected groups of gender-diverse young people.

  • This work is vital in contributing to international narratives regarding how different modes of service delivery may influence treatment decisions made by young people.


Gender-based distress may present at different times in a young person’s life. This may be from a young age,1 in adolescence (eg, due to the onset of puberty2) and/or may shift throughout development.3–5 When a young person experiences continued gender-based distress, this is termed gender dysphoria (GD) and they may attend specialist services to explore their feelings. For many, this exploration does not lead to subsequent seeking of physical interventions.6 However, some may seek physical interventions to align their bodies with their experienced gender. Such interventions include pubertal hormone suppressants (gonadotropin-releasing hormone analogues (GnRHas)) and gender affirming hormones (GAH), which support the development of secondary sex characteristics consonant with their identified gender. Surgical treatment options are not available through this service. Improvements in psychosocial mental health have been noted with GnRHa7 and GAH,8 and these interventions are presently accessed in over 25 international clinics under varying treatment regimens9 For instance, some clinics offer GAH treatment at earlier ages as they state that withholding treatment may be causing more harm.10 However, others suggest that earlier physical treatment may potentially cause an unwillingness to explore gender diversity and crystallise ideas around gender identity too early.3 5 11 What is not considered is that young people (YP) referred to endocrinology represent a highly selected cohort of all YP referred to specialist gender services.

In England, the Gender Identity Development Service (GIDS) is the only national service offering multidisciplinary care for YP in the British Isles (excluding Scotland and Northern Ireland). YP are supported in exploring their gender identity alongside the complexities that may make up their lives.12–18 In relation to physical treatment, the service uises a model of care that facilitates the use of GnRHa only after extensive psychosocial assessment and after the first signs of puberty, and GAH available around age 16 years, and only after approximately 1 year of GnRHa treatment. Referrals to adult gender identity clinics (GICs) are made at around age 18 years. The GIDS has seen considerable increases in referrals to the service,12 19 20 as has also been found in other European and American clinics.12 In particular, since 2010, there has been an increase in the ratio of assigned female YP,19 20 as has also been found elsewhere.20 21 Less is known about the subsequent decisions made by those referred to endocrinology. As such, the present research aimed to assess the numbers and demographics of YP referred for physical treatment (GnRHa and/or GAH) in the GIDS from 2017 to 2019 (cohort 1) and the trajectories of a subgroup of these YP, who were referred to endocrinology in 2017–2018 (cohort 2). This work can contribute to cross-comparison with other international clinics to further understanding about the demography of YP who opt for physical treatment pathways and to broaden understanding around the trajectories that YP may choose.

Materials and methods

Participants and methods

A retrospective cohort analysis was conducted assessing all referrals to the two endocrine liaison clinics from 1 January 2017- to 31 December 2019 with a view of starting GnRHa or GAH treatment under GIDS protocols (cohort 1). Data were extracted from an online patient records system.

Exclusion criteria for cohort 1 included referral to clinic for a pubertal assessment, fertility preservation or discussions regarding fertility, initial treatment discussions (pretreatment referral discussions), other endocrine concerns, where YP were privately accessing treatment (not under GIDS protocols; see Butler et al)22 and where treatment was not under University College London Hospital or Leeds Teaching Hospital. This related to cases in Ireland.

In-depth analysis of treatment pathways was undertaken for a sub-group of cohort 1, on those referred to endocrinology from 1 January 2017 to 31 December 2018 (cohort 2) as a review of referrals beyond 2018 had not been completed at time of analysis owing to the extensive nature of this data entry still being underway. Data were extracted in November 2020 using the timeframes specified: the first referral to endocrine period (January 2017–December 2019; cohort 1) to identify all referrals, and a subgroup of cohort 1 (January 2017–December 2018; cohort 2) to further assess trajectories through services up to the point of data extraction.

Referrals that did not fit the inclusion criteria were screened out prior to analysis. As most of the endocrine treatments are prescribed and administered by local general practitioners (GPs), endocrine clinics only providing recommendations to GPs to commence treatment. As such, exact start dates for commencement were not known. Thus patient consent at clinic was used as a proxy for treatment start dates. Stopping treatment data were collected from patient records and information from the endocrinology team. A complementary article specifically assessing all discharge destinations from endocrine clinics of a larger group of YP from 2008 to 2021 was analysed separately (see Butler et al).23 The present piece analyses demographics and pathways during YP’s time within the GIDS, with more detail surrounding how services were navigated by a sample of these YP (cohort 2).


All analyses were descriptive and focused on the demography of the cohorts assessed by gender assigned at birth. Data are reported as means, medians, SD, ranges and IQRs where relevant.



An overall sample of 668 YP (227 assigned male at birth (AMAB) (34%): 441 assigned female at birth (AFAB) (66%); mean age at endocrine referral: 15.4±1.6; median: 15.8) aged between 10.1 and 18.7 (IQR: 1.9) years were referred to endocrinology from 1 January 2017 to 31 December 2019 (cohort 1). The majority of these YP were 15+ years at referral (table 1). Figure 1 shows a breakdown of assigned gender by year of referral. It is important to note that cohort 1 data only include referrals to endocrinology with the intention of starting GnRHa or GAH and do not include the subsequent decisions made to pursue GnRHa or GAH treatment. The average age of YP attending first appointments at the GIDS was 14.2 (±2.1) years (median: 14.9; range: 5.1–17.7 years; IQR: 2.3). When compared with all YP attending a first appointment at GIDS between 2017 and 2019 (3165 first appointments in total), this sample represents a small cohort (21%) of the total. However, it is important to note that not all who attend a first appointment will choose an endocrine pathway.

Table 1

Mean (±SD) and median age, and age range (IQR) at referral to the GIDS, at first appointment at the GIDS and at referral to endocrinology by birth registered sex (assigned male at birth or assigned female at birth) for young people referred to endocrinology in 2017–2019 (cohort 1), and a separate breakdown for those referred to endocrinology in 2017–2018 (cohort 2)

Figure 1

Endocrine referrals at the Gender Identity Development Service (GIDS) by year and assigned gender at birth (assigned male at birth (AMAB) or assigned female at birth (AFAB)).

To learn more about trajectories, analysis of pathways of those referred to endocrinology from 2017 to 2018 was analysed (cohort 2). This resulted in a sample of 439 YP (154 AMAB (35%): 285 AFAB (65%); mean age at endocrine referral: 15.4±1.6; age range at endocrine referral: 10.1–18.7; IQR: 1.9) that were analysed (see table 1).

Trajectories through the GIDS after referral to endocrinology

Descriptive analysis of cohort 2 showed the mean age of consenting to access GnRHa was 15.8 (±0.1; age range: 11.0–18.4) and GAH was 17.3 (±0.1; age range: 15.8–19.0). A further breakdown by birth registered sex is provided in table 2.

Table 2

Mean (±SD) and median age and age range (IQR) when medical consent for gonadotropin-releasing hormone analogues (GnRHa) and gender affirming hormones (GAH) were recorded at endocrine clinic by birth registered sex (assigned male at birth or assigned female at birth) for young people referred to endocrinology in 2017–2018 (cohort 2)

Of those who were referred to endocrinology, 431 (152 AMAB; 279 AFAB) consented to GnRHa and 8 (2 AMAB; 6 AFAB) consented to GAH only (figure 2). Ninety-seven (23%; 45 AMAB; 52 AFAB) of these 431 were accessing GnRHa in the GIDS at time of analysis. One hundred and eighty-three (42%; 47 AMAB; 136 AFAB) consented to GAH treatment after GnRHa with the GIDS. Of the 183 who consented to GAH, 121 (66%; 30 AMAB; 91 AFAB) were referred to GICs, and 56 (31%; 18 AMAB; 38 AFAB) continued to access GAH with the GIDS. The average number of years from consent to GnRHa to consent to GAH was 1.3±0.02 (range: 0.5–2.6; table 2). Further data specifically assessing onward trajectories after discharge from endocrine services for this and wider cohorts of GIDS YP can be found in Butler et al.23

Figure 2

Trajectories of young people who accessed hormone treatment from a cohort attending the Gender Identity Development Service (GIDS) from 2017 to 2018. GAH, gender affirming hormone; GIC, gender identity clinic (adult services); GnRHa, gonadotropin releasing hormone analogues.

Stopping and recommencing treatment

Of those in cohort 2 who consented to GnRHa, 30 (7%; 9 AMAB; 21 AFAB) did not commence or stopped treatment (figure 3). The reasons for this included: not known (n=13), physical health problems (n=5), pausing to preserve fertility (n=4), transfer to a private provider (n=4), feeling unsure (n=3) or mental health concerns (n=1). Seventeen (4%) did not commence GnRHa with the GIDS after consenting to start or did not recommence after stopping. Thirteen are still accessing the service and so may consider treatment options in the future. None in cohort 2 who pursued GAH treatment decided to stop or pause treatment while at the service, although it is important to note that the time frame of accessing GAH in the GIDS is shorter before leaving the service and not all had been followed through to discharge.

Figure 3

Trajectories of young people who did not commence or stopped GnRHa treatment from a cohort attending the Gender Identity Development Service (GIDS) from 2017 to 2018. GAH, gender affirming hormone; GIC, gender identity clinic (adult services); GnRHa, gonadotropin-releasing hormone analogue.

Referral to adult GICs

Referrals to GICs were recorded for 237 YP (54%; 76 AMAB; 161 AFAB). Although some were still part of the GIDS and awaiting their appointment at GICs, 41 had been discharged (9%; 14 AMAB; 27 AFAB), and the remaining 161 (37%) were still accessing the GIDS (under age for referral to GICs). This analysis represents a snapshot in time. Full details of discharge outcomes are given in Butler et al.23 Qualitative information regarding reasons for decisions not to go onto GICs was not available.


This study aimed to explore the demographics and pathways followed by YP referred to endocrinology as part of the GIDS to gain a better understanding of treatment decisions.

More AFAB (66%) than AMAB (34%) adolescents were referred to endocrinology (cohort 1), and subgroup analysis (cohort 2) also showed larger numbers of AFAB adolescents on every pathway identified. This reflects more AFAB YP attending the GIDS in general,19 as has also been found internationally20 21; thus, it is difficult to know whether there are proportionally more assigned female YP accessing these pathways than assigned male YP. It is also important to note that this cohort represents a small sample (21%) of all YP accessing GIDS for a first appointment over this time period, although not all YP will choose to opt for an endocrine pathway in the service.

The average age of attending a first GIDS appointment for cohort 1 was at around 14 years with a referral to endocrinology at around 15 years. These adolescent years have been noted as a particularly difficult time for YP3 5 owing to advancing pubertal changes, distress over potential romantic relationships and greater shifts in social expectations.21 It is also important to note the long wait times prior to attending services for these YP, with many experiencing puberty on initial referral to the GIDS (around age 13–14 years in this cohort) enduring distress with the advancement of puberty while waiting to access services.

Of those in cohort 2 who consented to GnRHa, 23% accessed at the GIDS, and 42% subsequently consented to GAH. Referral for GAH was at around 17 years, which likely reflects the GIDS specifications of not offering GAH until approximately 16 years old or after approximately 1 year of GnRHa. Many of this sample accessing GAH (183 YP) accessed GnRHa at around age 16 years, hence the older mean age of accessing GAH.

The most common pathway identified involved consent to GnRHa, followed by accessing GAH and onward referral to a GIC (27% of the whole sample of 439). The majority of cohort 2 either continued treatment with GIDS or were referred to a GIC. This is in line with research that has been noted elsewhere.16 24 While some may argue that this may reflect an unwillingness to explore gender once GnRHa is accessed,3 5 11 there may be more plausible hypotheses. It may instead be indicative of this group being a highly selective sample of YP whose deeply held sense of gender identity remains consistent, and, after psychosocial assessment (as stated, there was approximately 1 year from first appointment at the GIDS to endocrine referral) and continued support while on physical treatment (for at least another year), they are accessing the treatment they feel they need.22

It is interesting to note that 7% of this cohort who consented to GnRHa either did not commence or commenced and stopped GnRHa with the GIDS. For some of these, private providers were sought instead. This is most commonly the case when service users desire GAH treatment at an earlier age, or before completing approximately 1 year of GnRHa treatment. Others opted for an onward referral to GICs when appropriate, likely owing to age and a desire to access GAH treatment over GnRHa. Of this sample, 17 YP (4% of the cohort) did not access GnRHa after consenting and either left the service or continued psychosocial treatment alone. The GIDS is only commissioned by National Health Service (NHS) England up to age 18 years, while other international gender services offer continued treatment within the same setting.16 25 Thus, further comparisons with international clinics to understand continuation of endocrine treatment after age 18 years was not possible.

Many gender diverse people only start to seek support and treatment in adulthood, though there is evidence to suggest that in some, the experience of GD is present in childhood.2 3 13 While it is not known if these experiences were present since childhood in this cohort, as physical treatments at the GIDS are considered alongside an extensive psychosocial assessment, and in line with Endocrine Society guidelines,26 it is likely that the present cohort had longstanding experiences of distress around their gender. It is also important to reiterate the long wait times experienced by YP before accessing services and the older age of accessing treatments noted in cohort 2. When these data are taken alongside the larger cohort of endocrine discharge outcomes presented by Butler et al, and the low rates of stopping treatment noted in this piece,23 considerations around the need for increased service provision, to allow for more timely treatment where indicated is evident.


This analysis only included quantitative data, thus further understanding of the circumstances around individual could not be explored. Collection of additional details regarding referrals to endocrinology in 2019 and 2020 was challenged due to the COVID-19 pandemic. It is important to acknowledge the impact this delay has had on gender diverse YP’s mental health.27

Moreover, information regarding the number of YP pursuing endocrine treatment as compared with all eligible active cases presenting at the service was not available. Accessing endocrine treatment is a pathway a smaller group of all YP attending services choose to follow despite potentially fulfilling physical eligibility criteria. The use of arbitrary cut-offs such as age would only provide crude and potentially misleading figures, as would comparisons with every open case in the service. Future research is required to consider how these numbers may be reached in a clinically meaningful way to allow for better understanding between those who choose a physical treatment pathway and those who do not. Furthermore, this study only presents findings from those referred to the GIDS; thus, the treatment trajectories outlined cannot be assumed to be similar for those accessing non-NHS services.


We assessed the demographics of YP referred to endocrinology clinics as part of the GIDS and for a subgroup (cohort 2) their onward trajectories through the service. The average age of referral for GnRHa was 15.4 years (cohort 1). The most common trajectory for cohort 2 comprised consenting to GnRHa (at 15.8 years) followed by consenting to GAH (at 17.2 years) and onward referral to a GIC. The second most common option was consenting to GnRHa before onward referral to GICs. The majority (54%) of cohort 2 were referred (or are in the process of referral) to a GIC, with 9% opting out of referral on leaving the service and the remainder were still actively part of the GIDS. Further research is required to understand how all YP referred to gender services navigate through them with the current level of knowledge and whether this has any effect on the outcome.

Data availability statement

No data are available. Owing to the sensitive nature of this patient data, and to ensure anonymity, data are not available to share.

Ethics statements

Patient consent for publication



  • Contributors UM conceptualised the research and methodology, carried out the screening and selection processes, analysed the data, drafted the manuscript and was responsible for overall content as the guarantor. PC critically reviewed the manuscript for important intellectual content, confirmed the data and contributed to manuscript revisions. GB confirmed the data and critically reviewed the manuscript. All authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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