Abstract

Introduction The aim of this study was to determine the annual age- and sex-specific prevalence of gender-affirming hormone and puberty blocker use among young people with a gender incongruence (GI) diagnosis in Norway.

Methods We integrated data from multiple Norwegian national registers to perform a nationwide register-based study of individuals with known sex assigned at birth who were born in the period 1975–2017 and resident in Norway for all or part of the period 2008–2022. We first calculated the annual age- and sex-specific incidence of GI diagnoses in the population. Then, we calculated the annual age- and sex-specific prevalence of androgen, estrogen, and puberty blocker use among individuals with a GI diagnosis who were under age 25 (for androgens and estrogens) or 18 (for puberty blockers) in the year that they collected the prescription.

Results The incidence of GI diagnoses has increased among youth in Norway, most notably since 2015 and with the largest increase among teens assigned female at birth. The prevalence of feminizing and masculinizing hormone therapy has increased in this period as well, but mainly among the oldest teens and young adults. The prevalence of puberty suppression is mostly low but has also increased since 2015, especially in recent years among teens assigned male at birth.

Conclusion The prevalence of gender-affirming hormone and puberty blocker use has increased among transgender youth in Norway, concurrently with an increase in the incidence of GI diagnoses.

What’s known on this subject Referrals of youth with gender incongruence have increased internationally. However, up-to-date nationwide data describing age- and sex-specific patterns of diagnosis and use of puberty blockers and gender-affirming hormones remain limited.

What this study adds Gender incongruence diagnoses have increased among youth in Norway since 2015. Gender-affirming hormone use rose among adolescents and young adults in this period, while puberty suppression remained low but increased, especially in recent years among adolescents assigned male at birth.

Competing Interest Statement

The authors have declared no competing interest.

Funding Statement

This work was funded by the South-Eastern Norway Regional Health Authority through the NORTrans Y-REG project (project ID 2024011). The funder had no role in the design, data collection, data analysis, or reporting of this study.

Author Declarations

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

This study protocol was reviewed and approved by the Regional Committees for Medical Research Ethics South East Norway (reference number 167265).

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

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I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

Footnotes

Conflict of interest disclosures: The authors have no conflicts of interest relevant to this article to disclose.

Funding: This work was funded by the South-Eastern Norway Regional Health Authority through the NORTrans Y-REG project (project ID 2024011). The funder had no role in the design, data collection, data analysis, or reporting of this study.

Data sharing statement: Deidentified individual participant data will not be made available. All incidence and prevalence data that we present are available as supplementary data.

Ethics statement: This study protocol was reviewed and approved by the Regional Committees for Medical Research Ethics South East Norway (reference number 167265).

Data Availability

Deidentified individual participant data will not be made available. All incidence and prevalence data that we present are available as supplementary data.

AbbreviationsAFABassigned female at birthAMABassigned male at birthATCAnatomical Therapeutic ChemicalGAHTgender-affirming hormone therapyGIgender incongruenceGnRHgonadotropin-releasing hormone