{"id":8989,"date":"2026-04-07T10:34:15","date_gmt":"2026-04-07T10:34:15","guid":{"rendered":"https:\/\/www.proefschriftmaken.nl\/portfolio\/marianne-van-der-loos\/"},"modified":"2026-04-23T08:27:26","modified_gmt":"2026-04-23T08:27:26","slug":"marianne-van-der-loos","status":"publish","type":"us_portfolio","link":"https:\/\/www.proefschriftmaken.nl\/en\/portfolio\/marianne-van-der-loos\/","title":{"rendered":"Marianne Van Der Loos"},"content":{"rendered":"","protected":false},"excerpt":{"rendered":"","protected":false},"author":8,"featured_media":13567,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"footnotes":""},"us_portfolio_category":[45],"class_list":["post-8989","us_portfolio","type-us_portfolio","status-publish","has-post-thumbnail","hentry","us_portfolio_category-new-template"],"acf":{"naam_van_het_proefschift":"The Dutch Protocol: Coming of Age","samenvatting":"Doel van dit proefschrift\n\nZoals beschreven is het gebruik van the Dutch Protocol omstreden door het gebrek aan studies die effecten op de lange termijn bekijken. Het doel van dit proefschrift is om licht te werpen op langetermijnuitkomsten van kinderen en adolescenten die werden doorverwezen naar de genderidentiteitskliniek van Amsterdam UMC, locatie Vrije Universiteit Amsterdam. Dit hebben we gedaan door (1) onderzoek te doen naar het (behandel)traject dat jongeren doorlopen, inclusief het mogelijk stoppen van de behandeling op latere leeftijd, en (2) het langetermijneffect van puberteitsremming gevolgd door genderbevestigende hormoonbehandeling op de botgezondheid te bestuderen.\n\nBelangrijkste bevindingen\n\nDeel 1 \u2013 Behandeltrajecten van transgender adolescenten\nIn Hoofdstuk 2 onderzochten we de trajecten die kinderen en adolescenten, verwezen naar de genderkliniek van Amsterdam UMC, locatie Vrije Universiteit Amsterdam, doorliepen. We ontdekten dat de sterke toename in recente aanmeldingen voornamelijk voortkwam uit een toename in personen met een vrouwelijk geboortegeslacht die \u2265 10 jaar oud waren bij intake. De gemiddelde leeftijd bij intake was over het algemeen hoger bij personen met een vrouwelijk geboortegeslacht dan bij personen met een mannelijk geboortegeslacht. Rond 2012 vond er een verschuiving plaats in de verhouding van geboortegeslacht richting personen met een vrouwelijk geboortegeslacht. Personen met een vrouwelijk geboortegeslacht begonnen vaker met puberteitsremming dan personen met een mannelijk geboortegeslacht. De belangrijkste reden hiervoor leek te zijn dat personen met een mannelijk geboortegeslacht minder vaak voldeden aan de criteria voor de diagnose genderdysforie. Vrijwel alle jongeren die puberteitsremmers gebruikten, startten nadien met genderbevestigende hormoonbehandeling. Het verdwijnen van genderdysforie was de belangrijkste reden om te stoppen met puberteitsremming. Er werd een opvallend verschil gevonden tussen het percentage personen dat een genderbevestigende operatie onderging v\u00f3\u00f3r en na juli 2014. In juli 2014 vond een wetswijziging plaats, waarbij het niet langer vereist was dat men een genderbevestigende operatie onderging om het juridische geslacht te veranderen.\n\nIn Hoofdstuk 3 werd het continueren van genderbevestigende hormoonbehandeling bij mensen die volgens the Dutch Protocol waren behandeld bekeken. We ontdekten dat 98% van deze groep de hormoonbehandeling voortzette. Er werd geen verband gezien tussen stoppen van de behandeling en leeftijd bij het eerste bezoek, leeftijd bij de start van behandeling, puberteitsfase bij het begin van puberteitsremming, gonadectomie (verwijdering van de geslachtsklieren), het jaar waarin mensen voor het eerst de kliniek bezochten, of het jaar waarin de genderbevestigende hormoonbehandeling werd gestart.\n\nDeel 2 \u2013 Botgezondheid bij transgender adolescenten\nDe ontwikkeling van botdichtheid tijdens puberteitsremming en genderbevestigende hormoonbehandeling, en na langdurige hormoonbehandeling werd bestudeerd in Hoofdstuk 4. In deze studie zagen we dat de botdichtheid bij personen met een vrouwelijk geboortegeslacht op de lange termijn niet veranderde. Bij personen met een mannelijk geboortegeslacht bleef de botdichtheid stabiel ter plekke van de heup. De botdichtheid van de lage (lumbale) wervelkolom bleek echter af te nemen. Mogelijk komt dit door een relatief lage dosering oestradiol in de beginfase van de hormoonbehandeling. In hoofdstuk 5 zagen we namelijk dat de botdichtheid na twee jaar hormoonbehandeling meer toenam bij transmeisjes die een hogere dosering oestradiol hadden.\n\nEen andere verklaring voor de afname van botdichtheid in de lumbale wervelkolom werd onderzocht in Hoofdstuk 6. In deze studie werd gekeken naar het natuurlijk beloop van botdichtheid bij adolescenten met genderdysforie die nog niet waren gestart met puberteitsremming of genderbevestigende hormonen. Bij personen met een mannelijk geboortegeslacht bleek de botdichtheid met de leeftijd af te nemen. Deze relatie werd niet waargenomen bij personen met een vrouwelijk geboortegeslacht. We ontdekten dat de afname van botdichtheid deels was toe te schrijven aan een afname van spiermassa. Deze bevinding suggereert dat hormoonbehandeling niet de enige reden is voor de gevonden afname in botdichtheid op de lange termijn. Hoofdstuk 7 toonde aan dat de geslachtsspecifieke ontwikkeling van botgeometrie tijdens de genderbevestigende hormoonbehandeling het beloop van de genderidentiteit volgde wanneer vroeg in de puberteit met puberteitsremming werd gestart. Wanneer de puberteitsremming later in de puberteit werd gestart, volgde de botgeometrie het beloop van het bij de geboorte toegewezen geslacht. Botgeometrie is een belangrijk onderdeel van botsterkte, dus dit kan gevolgen hebben voor het risico op botbreuken bij transgender personen. In een breder perspectief suggereren de resultaten dat er een \u201cwindow of opportunity\u201d is in de vroege puberteit waarin de belangrijkste effecten van geslachtshormonen op botgeometrie worden uitgeoefend.\n\nGevolgen voor de praktijk\n\nDit proefschrift toont aan dat behandeltrajecten voor transgender jongeren divers zijn, en afhankelijk van individuele kenmerken en wettelijke vereisten. Om aan individuele behoeften te voldoen moet de zorg voor adolescenten met genderdysforie maatwerk zijn. Na de Nederlandse wetswijziging in 2014, waardoor mensen hun geslacht konden veranderen in de geboorteakte zonder een gonadectomie te ondergaan, besloten veel mensen hun geslachtsklieren te behouden. Dit heeft aanzienlijke gevolgen voor het behoud van vruchtbaarheid. Tevens vergt dit een andere kijk op gynaecologische zorg voor personen met een vrouwelijk geboortegeslacht, zoals het onderdrukken van menstruatie, evaluatie van abnormaal vaginaal bloedverlies of obstetrische zorg. Bijkomend moeten zorgverleners deze personen informeren over screeningsprogramma\u2019s voor borst- en baarmoederhalskanker, gezien de nog grotendeels onbekende langetermijneffecten van hormoonbehandeling op de voortplantingsorganen.","summary":"OF THE MAIN FINDINGS AND GENERAL DISCUSSION\n\nIn this chapter the main findings of this thesis are summarized. Subsequently overall strengths and limitations, and clinical implications are provided. Since adolescent transgender healthcare remains controversial, the findings of the studies presented in this thesis will also be discussed within the societal context. Finally, suggestions for further studies are made.\n\nPart 1 \u2013 Trajectories of transgender adolescents\nIn Chapter 2 we examined treatment trajectories in children and adolescents referred to the gender identity clinic of the Amsterdam UMC, location Vrije Universiteit Amsterdam. It was found that the steep increase in recent referrals is mainly generated by pubertal (i.e. \u2265 10 years of age at intake) individuals assigned female at birth (AFAB). The overall median age at intake is higher in AFAB than in individuals assigned male at birth (AMAB). A shift in ratio of sex assigned at birth towards AFAB occurred around 2012. The observed shift in AMAB:AFAB ratio is in line with previous studies. Age at intake gradually increased over time, possibly as an unfortunate result of a long waiting list to enter the gender identity clinic. This only slightly affected the age at which medical treatment, gonadotropin-releasing hormone agonist (GnRHa) and\/or gender-affirming hormones (GAH), was started. Almost half of AMAB started GnRHa, versus three-quarters of AFAB. The main reason for this seemed that AMAB were less likely to meet the criteria for a diagnosis of gender dysphoria. This was also the case in a recent study performed in the USA. The proportion of people starting GnRHa has mainly increased over time in individuals first visiting < 10 years of age. Compared with AFAB, AMAB were 1.5 years younger when starting GnRHa. Nearly all AMAB and AFAB on GnRHa went on to start GAH. Age at start of GAH was just slightly higher in AFAB. Keeping in mind the pronounced age difference at start of GnRHa, this means that in general AMAB were on mono GnRHa treatment longer. In the sporadic cases GnRHa treatment was discontinued, the main reason was remission of gender dysphoria. Additionally, a pronounced difference was found between the percentages of persons undergoing gonadectomy before and after July 2014, when a change in law no longer required people to undergo gonadectomy to change their legal sex. Continuation of GAH treatment in people treated according to the Dutch Protocol was assessed in Chapter 3. By merging this particular cohort to both the hospital\u2019s prescription registry and the prescription registry that is maintained nationally by Statistics Netherlands (Centraal Bureau voor de Statistiek; CBS), we found that 98% continued GAH treatment. Discontinuation was not associated with age at first visit, age at start of GnRHa treatment, age at start of gender-affirming hormone treatment, puberty stage at start of GnRHa treatment, gonadectomy, year in which people first visited, or year in which GAH treatment was started. Although the subject of continuation is studied by Roberts et al., who investigated continuation of GAH four years after start of treatment, a similar study in this population has not been reported. The Roberts study found 74.4% of individuals starting GAH before age 18 had continued treatment. However, it does not mention how many of these adolescents were using puberty suppression prior to GAH.\n\nPart 2 \u2013 Bone health in transgender adolescents\nBMD development during GnRHa and GAH treatment, and after long-term GAH treatment was assessed in Chapter 4. At the lumbar spine, total hip, and femoral neck BMD Z-scores decreased during GnRHa treatment in both AMAB and AFAB, which has become a common finding. Previous studies assessing BMD Z-scores showed they did not completely catch up after short-term GAH. However, in our study at long-term follow-up a compensatory increase in bone mineral accrual was seen at all three regions in AFAB, yielding BMD Z-scores similar to pretreatment levels. In AMAB, BMD Z-scores did catch up with pretreatment levels after long-term GAH treatment at the total hip and femoral neck, but not at the lumbar spine. A possible reason for this might be sought in the relatively low dosage of estradiol in the first stage of GAH. This hypothesis was studied in Chapter 5. In this chapter the effect on BMD development of different estradiol dosages was studied in trans girls. The study consisted of three groups who were either treated with 2 mg estradiol, 6 mg estradiol, or 100-200 \u03bcg ethinyl estradiol (EE). Treatment with 6 mg estradiol or EE was given to limit growth in a selective cohort of trans girls. All individuals had received GnRHa for at least one year prior to estradiol treatment, and started treatment before turning 18 years of age. After two years of GAH, a greater increase in BMD Z-score was found in the groups treated with EE than in the group treated with 2 mg estradiol. Moreover, Z-scores caught up with pretreatment levels in the 6 mg and EE group at the lumbar spine, at the total hip, and at the femoral neck. In the 2 mg group catch up of BMD Z-score was only seen at the total hip. This suggests that BMD development is indeed associated with estradiol dosage. An alternative explanation for the persistently low lumbar spine BMD Z-score during GAH treatment is considered in Chapter 6. This study demonstrated an inverse relationship between BMD Z-score and age in AMAB diagnosed with gender dysphoria who had not yet started medical gender-affirming treatment. This relationship was not observed in AFAB. This finding suggests that other factors besides medical treatment affect BMD development in AMAB. We found that the decrease in BMD Z-score was partly attributable to a decrease in height-adjusted lean mass Z-score in AMAB, indicating physical exercise is a key factor in the downward sloping curve of BMD Z-score during treatment as well. This explanation was also suggested by others. Chapter 7 showed that sex-specific development of hip bone geometry during GAH treatment followed the course of the gender identity only when puberty suppression was started in early puberty. When puberty suppression was started longer after onset of puberty bone geometry followed the trajectory of the sex assigned at birth. This study deepens our understanding of bone strength in transgender individuals as well as sex-specific bone development during puberty in the general population. Bone geometry is an important part of bone strength, so this could hold implications for fracture risk in transgender individuals. As trans women starting puberty suppression in early puberty obtain bone geometry similar to cis women, fracture risk might be higher compared to trans women starting in late puberty. In a broader perspective, the results suggest there is a particular critical window in early puberty during which the main effects of sex hormones on bone geometry are exerted.\n\nStrengths & limitations\nFirstly, this thesis provides an overview of general characteristics, diagnostic and treatment trajectories in a relatively new, and growing, population. All data originate from the gender identity clinic of the Amsterdam UMC, location Vrije Universiteit Amsterdam, the largest pediatric gender identity clinic in the Netherlands. This center has provided transgender health care to the majority of transgender people medically transitioning. Thus, results from this center are a fair representation of transgender adolescents in the Netherlands. People were treated uniformly according to the well documented Dutch Protocol, and data were collected and stored systematically. Another valuable asset is the unmatched duration of follow-up in most studies. As the Dutch Protocol originates in this gender identity clinic there are 20 years\u2019 worth of data for studying trends and long-term follow-up. Secondly, linking our dataset with data from Statistics Netherlands (CBS), the institution collecting nationwide statistical information about the inhabitants of the Netherlands, is a solid component of this thesis. Thirdly, it gained much needed insight into bone health in both transgender adolescents not yet receiving medical treatment, and in those treated with puberty suppression followed by GAH. The latter is of particular interest, as long-term effects of puberty suppression and subsequent GAH on bone health were unknown, yet highly anticipated.\n\nA limiting feature is the retrospective design of most studies, restricting research questions by missing data which were either collected incompletely, such as vitamin D concentrations, or not collected at all, such as physical exercise scores. Moreover, all conclusions were drawn from quantitative data. For example, continuation of treatment was assessed based on issued prescriptions, but whether discontinuation was related to regret was not investigated with qualitative interviews. Additionally, BMD Z-score is not the sole factor contributing to the perhaps more clinically relevant parameter of fracture risk which was not studied. Lastly, although studying a population from one center has its advantages as mentioned, this also limits the applicability to practice outside the Netherlands.\n\nClinical implications of this thesis\nChapter 2 shows that treatment trajectories, including the start of medical treatment, and desire for gender-affirming surgeries are diverse and subject to individual characteristics and legal requirements. Adolescent transgender health care should be tailored to fit individual needs. After the abrogation of a Dutch law, allowing people to change their legal sex without having to undergo gonadectomy, a much larger proportion of individuals decided to keep their reproductive system in situ. This has considerable consequences for preservation of fertility potential. Additionally, AFAB might have changed gynecological needs, such as suppression of menstruation, evaluation of abnormal uterine bleeding, or obstetric care. Furthermore, as long-term effects of GAH on the reproductive organs are largely unknown, clinical providers should make persons opting for this approach aware of population screening programs for breast and cervical cancer.\n\nThe high percentage of continuation of GAH found in Chapter 3 is reassuring and suggests a low risk of regret in individuals starting treatment in adolescence. It should be noted that all participants had a diagnostic assessment prior to treatment initiation and were professionally supported during their transition. After comprehensive assessment by a mental health professional with ongoing involvement of a multidisciplinary team, risk of regret should not be a reason to withhold medical treatment.\n\nThe most pressing issues regarding long-term bone health in transgender adolescents treated with puberty suppression are answered in Chapter 4. Results in AFAB are reassuring as BMD Z-scores had caught up with pretreatment levels after long-term GAH. Provided there are no other indications for DXA, routine DXA-scans in this population, that started medical treatment in late puberty, do not seem necessary. Yet, conclusions drawn on the lumbar spine region in AMAB are less encouraging. During treatment with GnRHa BMD Z-score decreased, without compensatory catch-up after long-term GAH. However, Chapter 5 and Chapter 6 provided possible explanations for this decrease, as BMD development was associated with a lower dosage of estradiol during GAH treatment and with lower lean mass already before the start of puberty suppression. This last finding may be a result of differences in lifestyle, more particular in levels of physical activity that promote bone accumulation, between cisgender boys and transgender girls. Decreased lean mass, however, did not explain the diminished Z-scores completely. Other factors, such as deficient sunlight exposure resulting in low vitamin D, or reduced calcium intake, might hamper proper bone mass development in these individuals. Altogether, in AMAB the lumbar spine region remains a point of concern. Lifestyle factors and estradiol treatment should be optimized, stimulating maximum BMD accrual to mitigate the risk of osteoporosis later in life. It is remarkable that an ever-growing group of healthy children and adolescents have reduced bone mass accrual during puberty, possibly due to altered lifestyle, but claiming the treatment with puberty suppression in itself alone results in poor bone health would be erroneous. It is of great importance that transgender adolescents at risk of inadequate bone mass development are recognized early on, and properly advised even before the start of medical treatment. Routine DXA scans remain important to monitor bone health in AMAB and should be done at least before start of GnRHa and GAH and until an adequate peak bone mass has been achieved.\n\nSocietal considerations\nAlthough advocated by many, the Dutch Protocol has received heavy criticism as well. At the root of the criticism is a fear for adverse physical, cognitive, and psychosocial outcomes. Additionally, some raise ethical issues, challenging the treatment of minors for gender dysphoria on moral grounds, and questioning whether young adolescents are competent to make an informed decision on a life-changing treatment. In contrast, others have condemned the Dutch Protocol because of the crucial part the psychological assessment plays. They consider fulfilling certain diagnostic criteria required to start treatment as \u201cgatekeeping\u201d: a situation when healthcare providers control access to care by adhering to strict criteria. A different approach is the so-called \u201cinformed consent model\u201d. This model puts emphasis on respecting people\u2019s autonomy and decision-making capacity, and intends to reduce barriers, including waiting lists, to access medical transgender care. It does not require evaluation of mental health prior to starting medical transgender care. Although waiting lists to enter gender identity clinics constitute a major obstacle, a diagnostic assessment seems of added value as Chapter 2 showed that the majority of people not starting GnRHa did so because a diagnosis of gender dysphoria could not be established. It is unclear how many of these individuals would have started puberty suppression in an informed consent model, but possibly more might have started who would have decided to detransition later on. Although detransitioning in later life is by no means ruled out by a diagnostic and psychological evaluation prior to initiating treatment, Chapter 3 did find that very few individuals who started puberty suppression in adolescence followed by GAH subsequently stopped using GAH. This result can only be translated to individuals following the diagnostic approach according to the Dutch Protocol, including psychological assessment, but is reassuring regarding the risk of detransitioning in this particular population.\n\nAn increase in referrals amongst children and adolescents, and a sharp rise in pubertal AFAB requesting care as noted in Chapter 2 adds another degree of uncertainty to treating transgender adolescents: whether or not recently referred adolescents are comparable to the ones for whom the Dutch Protocol was originally designed and evaluated. Although a satisfactory explanation for the ratio strongly favoring AFAB has not yet been found, we can speculate about possible reasons. First, gender dysphoria might occur more frequently in AFAB. Reasons for this may include biological factors such as in utero exposure to abnormal levels of sex steroids or endocrine-disruptive chemicals, but studies have not corroborated these thoughts. Second, the observed imbalance could reflect sociocultural precepts either urging AFAB to seek care more often or at an earlier age, and\/or restricting AMAB to seek care. Possibly, AFAB can find their way to gender identity clinics more easily because in most Western societies it is more socially accepted for AFAB to present as gender diverse than for AMAB. A patriarchal society in which masculinity is valued above femininity, or in which being male is the path of least resistance, might play a role in this. However, it is unclear how this relates to the ratio originally favoring AMAB just after the introduction of the Dutch Protocol. Alternatively, the role of (social) media should be considered. Transgender and gender diverse-related items are appearing in the media exponentially, and young people are increasingly exposed to (social) media. Perhaps young AFAB are more susceptible to this coverage, and triggered to question their own gender identity, but reliable evidence on this is lacking completely. In Chapter 2 it was shown that the proportions of adolescent AFAB starting GAH were more or less similar for individuals first visiting before or after age 10. Additionally, Chapter 3 demonstrated continuation of GAH was similar in AFAB starting GAH before 2012 and after 2012. This suggests there are no major differences in persistence of gender dysphoria after start of puberty suppression in prepubertal and pubertal AFAB, nor after start of GAH in more recently referred AFAB.\n\nFuture studies\nAlthough this thesis greatly contributes to the knowledge on long-term outcomes of the Dutch Protocol, long-term studies on gender-affirming treatment in adolescents, as well as the capacity of adolescents to make informed decisions about their healthcare, remain crucial to improve safety of transgender health care to adolescents. Unexplored areas of interest include effects on cardiovascular health and cognitive functioning. Another objective should be the long-term efficacy of the Dutch Protocol, investigating whether starting medical treatment in adolescence improves mental health outcomes and well-being. As the number of referrals keeps increasing, it is important to find cogent reasons for the shift in ratio of referrals to, mainly pubertal, AFAB, and whether there are different characteristics of these individuals that challenge diagnostic certainty and may influence long-term outcomes of the current protocol. Furthermore, relatively more people choose to not undergo gonadectomy and keep their reproductive organs in situ. Long-term outcomes regarding the potential risk of malignant transformation due to continued exposure to exogenous sex hormones need to be studied. Further opportunities for exploration are the persistent low lumbar spine BMD Z-score in AMAB after long-term GAH, and potential consequences in terms of fracture risk.\n\nConclusion\nAs a whole, this thesis shows a low risk of discontinuing GAH in individuals starting puberty suppression in adolescence prior to GAH and largely refutes the historical concerns regarding long-term bone health. It adds scientific arguments to a discussion now mainly depending on expert opinion, political and ideological concerns. This thesis could help guide the highly polarized public and political debate regarding treatment for gender dysphoria in adolescents. However, more long-term studies, in all domains, are required to inform medical practice, policy decisions, and public discourse, ultimately contributing to a more just and evidence-based treatment perspective for transgender and gender diverse adolescents.","auteur":"Marianne Van Der Loos","auteur_slug":"marianne-van-der-loos","publicatiedatum":"15 maart 2024","taal":"EN","url_flipbook":"https:\/\/ebook.proefschriftmaken.nl\/ebook\/mariannevanderloos?iframe=true","url_download_pdf":"","url_epub":"","ordernummer":"FTP-202604071030","isbn":"978-94-6469-817-6","doi_nummer":"","naam_universiteit":"Vrije Universiteit Amsterdam","afbeeldingen":13567,"naam_student:":"","binnenwerk":"","universiteit":"Vrije Universiteit Amsterdam","cover":"","afwerking":"","cover_afwerking":"","design":""},"_links":{"self":[{"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/us_portfolio\/8989","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/us_portfolio"}],"about":[{"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/types\/us_portfolio"}],"author":[{"embeddable":true,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/comments?post=8989"}],"version-history":[{"count":1,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/us_portfolio\/8989\/revisions"}],"predecessor-version":[{"id":8992,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/us_portfolio\/8989\/revisions\/8992"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/media\/13567"}],"wp:attachment":[{"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/media?parent=8989"}],"wp:term":[{"taxonomy":"us_portfolio_category","embeddable":true,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/us_portfolio_category?post=8989"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}