Amsterdam Cohort Onderzoek Genderdysforie (ACOG)


Amsterdam Cohort Onderzoek Genderdysforie (ACOG)


Gender Dysphoria (GD) is the feeling of incongruence between the experienced gender and the assigned sex. Persons with severe gender dysphoria, may wish to change their body in line with their gender identity by medical treatment. Once GD is diagnosed, the person may start with hormone treatment  to acquire more masculine or feminine features, and later on, if desired, gender confirming surgery. The care of people with gender dysphoria is complex and sustained, and involves many disciplines which all cooperate within the Center of Expertise on Gender Dysphoria. The treatment is organized in a health care regime which takes more than 4 years.

The Center of Expertise on Gender Dysphoria of VUmc is the only Center in the Netherlands that offers a complete package of multidisciplinary care for gender dysphoric people of all ages. More than 5,000 patients have been treated in this center, and annually around 400 adults, and 200 adolescents and children present themselves for treatment. Internationally, the center is well known for its comprehensive care on gender dysphoria, with twelve different specialties involved, including psychological and somatic oriented specialties.

The ‘Amsterdam Cohort Onderzoek Genderdysforie’ (ACOG) aims to better understand the condition, to better understand its development from childhood to adulthood, to better understand the effects and side effects of treatment, and to develop and improve quality of care for individuals with gender dysphoria of all ages.

Cohort Study Adults

In this prospective cohort study, data is collected during diagnostic and therapeutic phases patients go through:

  • at entrance in the clinic;
  • during the diagnostic procedure;
  • at diagnosis;
  • before the start of cross-sex hormone treatment;
  • at 3, 6, 9 and 12 months of cross-sex hormones;
  • before gender confirming surgical interventions;
  • 1 year after surgery;
  • long-term FU.

Research questions

  • Factors that predict treatment outcome in terms of satisfaction, quality of life, psychological and sexual functioning
  • Short and long term effects of hormone treatment on metabolic parameters, bone densitometry, development of secondary gender characteristics, physical wellbeing, side-effects and (rare) complications such as thromboembolic events .
  • Comparison of surgical techniques with regard to complications, function and aesthetics.


ACOG collaborates in the ‘European Network for the Investigation of Gender Incongruence’ with other European centers that provide care for individuals with gender dysphoria: University Hospital Ghent, Belgium; Rikshospitalet University Hospital Oslo, Norway, Institut fur Sexualforschung, Hamburg, Germany, University of Florence, Italy, and University Hospital of Belgrade, Serbia. These centers agreed to use the same instruments during the diagnostic procedure and treatment.


Thus far (nov 2014) 1750 adults have entered the study. Endocrinological data of 277 patients in have been collected.

Cohort Study Children and Adolescents

In children and adolescents, a distinction is made between prepubertal children, for whom no medical intervention is required, and pubertal adolescents, who might be eligible for medical intervention by puberty suppression and subsequent cross-sex hormones and gender-confirming surgery at the respective ages of 12, 16 and 18 years old.

In this prospective cohort study, data is collected during the diagnostic and treatment phases children and adolescents and their families go through:

Pre-pubertal children:

  • at entrance at the clinic ;
  • at diagnosis;
  • if persisting, than at re-entrance at the clinic when puberty has started;
  • long term follow up.

Pubertal adolescents:

  • at entrance at the clinic;
  • at diagnosis;
  • at start puberty suppression;
  • during treatment with puberty suppression;
  • at start cross-sex hormones;
  • during treatment with cross-sex hormones;
  • before gender confirming surgery
  • 1 year after gender confirming surgery
  • long term follow up

Research questions

  • psychosexual outcome of children with gender dysphoria, factors that predict persistence or desistence, effects of early social transitioning, effects of parenting styles and personality characteristics;
  • factors that predict treatment outcome in adolescents in terms of capacity for informed consent, treatment satisfaction, quality of life, psychological and psychiatric functioning and sexual functioning;
  • short and long term outcome of early medical interventions, especially puberty suppression, on metabolic parameters, bone densitometry, growth, physical wellbeing, side-effects and (rare) complications such as hypertension;
  • outcome of surgical techniques in adolescents with , due to puberty suppression, less developed secondary sex characteristics, aesthethics and function.


ACOG collaborates with regard to adolescents with gender dysphoria in the Adolescent Gender Identity Research (AGIR) study with several other centers around the world that provide care for transgender adolescents, among which are: University Hospital Ghent, Belgium; University of Florence, Italy; Tampere University Hospital, Finland; Tavistock Clinic, London, UK; Center of Addiction and Mental Health, Toronto, Canada; Center for Sexual Health, Minneapolis, US; Lurie’s Children’s Hospital of Chicago, US.


So far, data have been collected of around 550 prepubertal children and almost 700 adolescents referred to the clinic since 1980 and 1987 respectively.

Contact information

Prof. dr. M. den Heijer (Department of Internal Medicine, head of Center of Expertise on
Gender Dysphoria,
Dr. B.P.C. Kreukels (Department of Medical Psychology,
Dr M.G. Mullender (Department of Plastic Surgery,
Dr. T.D. Steensma (children, Department of Medical Psychology,
Dr. A.L.C. de Vries (adolescents, Department of Child and Adolescent Psychiatry,

[updated 2015-01-15]