Pharmac data showed the total number of nine to 17 year olds on puberty blockers had increased from 137 in 2010 to 703 in 2020. File picture. Photo: 123RF
The number of children prescribed puberty blockers because they do not identify with their assigned gender has increased exponentially in the last decade, according to Pharmac data.
The Ministry of Health (MOH) has recently updated its information on puberty blockers on its website to remove the words "safe and reversible" - but still endorses the Professional Association for Transgender Health Aotearoa (PATHA) guidelines, which states they are "considered to be fully reversible".
Youth health doctor Dame Sue Bagshaw, who pioneered gender-affirming care for young people, said they had excellent results, particularly for those who go on to physically transition.
"Otherwise you get irreversible effects from their normal puberty which then need a lot of surgery, etceteras, to reverse ... breast development and things like that."
Puberty blockers eased distress and allowed children time to fully explore their gender options, she said.
However, some clinicians and families argued there was insufficient evidence to prove the benefits outweighed the risks.
Bianca* said more than five years into gender transition, her child's mental and physical health was not better - it was worse.
Puberty blockers were not "a simple pause button" as advocates claimed, she said.
"The side effects of those were terrible. It was basically like going through menopause... sweats, irritability, real fatigue, weight gain."
Puberty blockers - developed to treat very early puberty in young children - have been prescribed for gender dysphoria since about 2010 in New Zealand.
Pharmac data showed the total number of nine to 17 year olds on puberty blockers had increased from 137 in 2010 to 703 in 2020.
Tavistock gender identity clinic, which serves England and Wales, will close its doors early next year after a highly critical review, which found children's care was being compromised, amid huge waiting list blowouts.
The number of referrals to the service went from 138 in 2010/11 to 2383 in 2020/21.
Tavistock is being replaced by regional teams integrated with mental health services to provide holistic care.
'Many unknowns' about puberty blockers' long-term effects - paediatric specialist
Paediatric specialist Dr Hilary Cass, who headed the inquiry, noted there were still "many unknowns" regarding the long-term effects of puberty blockers and cross-sex hormones.
Brain maturation - including "development of frontal lobe functions controlling decision making, emotional regulation, judgement and planning ability" - could be temporarily or permanently disrupted at a time when children were making decisions, which would affect the rest of their lives, she said.
"This raises a secondary question of whether there is a critical time window for the processes to take place, or whether catch up is possible when oestrogen or testosterone is introduced later."
Furthermore, the role of adolescent sex hormones in driving the development of both sexuality and gender identity through the early teen years was not yet understood, Cass said.
"We therefore have no way of knowing whether, rather than buying time to make a decision, puberty blockers may disrupt that decision-making process."
The report noted there had been none of the quality controls usually applied to new treatments, and a lack of consistent data collection.
Plea for independent review of puberty blockers
The Ministry of Health recently updated advice on its website, to remove the description of puberty blockers as a "safe and reversible medicine".
The ministry declined RNZ's request for an interview about this change, but in a written statement said it was a "rapidly evolving" field and emerging information was being reviewed and assessed.
It subsequently clarified in other media statements that it continued to endorse the PATHA guidelines, which stated: "Puberty blockers are considered to be fully reversible and allow the adolescent time prior to making a decision on starting hormone therapy".
Medical epidemiologist Charlotte Paul, an emeritus professor at Otago University, has called for an independent review and tighter rules.
"The New Zealand Guidelines for Gender Affirming Care do not refer to the fact that this is an unapproved indication, or to the Medical Council guidelines and the need to ensure that patients know that this is an unapproved indication."
New Zealand was out of step with many other countries, which were moving to a more cautious approach, she said.
A review in Finland last year concluded psychosocial support and exploratory therapy should be the first-line therapy for gender dysphoria, which was also the recommendation in France.
"And in Sweden, they ended in 2022 all use of puberty blockers for minors outside of clinical study and they said that there was some medical harm and uncertainty of benefit," Paul said.
"And it looks as if even in their clinical studies, they won't include anyone under 16."
Dr Sue Bagshaw Dr Sue Bagshaw said they puberty blockers had excellent results, particularly for those who went on to physically transition. Photo: RNZ
'We should be cautious about any medication' - Dame Sue Bagshaw
Dame Sue Bagshaw, who has many transgender patients at her Christchurch youth practice, conceded there were some unknowns about the long-term effects of puberty blockers, particularly on bone density.
However, the same could be said of many drugs, and that was not a reason to stop prescribing them, she said.
"Of course we should be cautious, we should be cautious about any medication.
"We should also be cautious about young people who suicide. Or attempt to."
A 2019 survey of trans and non-binary people conducted by the University of Waikato found more than half had seriously thought about attempting suicide and 12 percent had made a suicide attempt in the past 12 months.
The study suggested when trans and non-binary people were supported by their families or community, it could save lives.
"If you're going to say 'let's not use them' [puberty blockers], we're going to have redouble our efforts to ensure the mental health of transgender diverse young people is looked after," Bagshaw said.
"And at the moment, it's not."
Offering psycho-social support as first-line treatment for gender dysphoria in young people was challenging, she said.
"It's actually quite difficult to help them to understand that they're being listened to without doing something, and that's the nature of brain development and it's also the nature of short appointment times."
Psychological interventions were also expensive, she said.
Dame Sue was not surprised or concerned that New Zealand's prescribing rates were higher than other countries.
"We're a small country, word travels faster by word of mouth.
"Obviously in the last 10 years it's gone up because we've now got societal permission to do that."
According to the Cass report, it was debatable whether puberty blockers bought time or locked a young person into gender transition.
Data from both the Netherlands and a study conducted by Tavistock found almost all children and young people put on blockers went on to sex hormone treatment (96.5 percent and 98 percent respectively).
*Name changed to protect identity.
