Puberty blocker prescriptions fall, after decade of rise

The number of children and young teens prescribed puberty blockers has fallen, after dramatic increases in the last decade.

Research published in the NZ Medical Journal on Friday shows use of the hormone-suppressing drugs was up to seven times higher here than in Britain.

According to the study:

• Use of puberty blockers increased from 2011 (when guidelines for use to treat gender-related distress were introduced), accelerated rapidly between 2014 then fell from 2022
• For those aged 12-17, "first use" was fewer than six each year from 2006 to 2008, increased from 2009 then more steeply from 2016 to 2021 (148) before declining
• First use among those aged 0-11 also rose steeply and fell, but it is unclear what proportion of this use was for gender dysphoria
• Cumulative use in New Zealand was 1.7 times higher than in the Netherlands, 3.9 times higher than Denmark and between 3.5 and 6.9 times higher than England and Wales.

For transgender kids unhappy about the mismatch between their developing bodies and gender identity, puberty blockers stop physical changes and ease their distress. However, there are growing questions internationally over the safety and effectiveness of the drugs.

The study's lead author, epidemiologist Professor Charlotte Paul, said researchers used Pharmac data to track use of blockers over time for zero to 11-year-olds, and 12- to 17-year-olds, between 2006 and 2023.

It was assumed that those in the older age group were mostly prescribed blockers to treat gender-related distress, rather than delaying precocious puberty, which was still the use approved by Medsafe, she said.

"The number of individuals given puberty blockers each year increased from about 50 in 2011, which is when guidelines for use for gender related distress were introduced, to about 400 in 2022, which is an eight times increase."

Researchers were surprised to find that first-time prescriptions started falling steeply in 2022, she said.

"We can only speculate but we think that the information must have been getting through to New Zealand about cautions, particularly in Europe and worries that had been voiced by medical professionals. And we presume that clinicians and parents were becoming aware of these and taking a more cautious approach."

'Time to think' - or 'locked in' to a medical pathway?

One mother, whose child went on puberty blockers at 14, said it was a huge relief at the time.

"When she had her period, it was hell to be honest - she was distraught."

The parents followed clinical advice and supported their child to medically transition - so it was a shock when she later decided to revert to her sex assigned at birth.

"We were following the best advice at the time. The child was so distressed, I don't know what would have happened if we'd denied blockers.

"But we do now question whether there should have been more support from a psycho-social perspective to explore what was going on, and whether this would have resulted in less invasive options and outcomes."

The woman said while transition was not the right thing for her daughter, she and her family remained very supportive of the need for transgender children to get the right treatment.

Another parent said blockers were helpful, and her child was now "a happy, well-adjusted adult".

"Sexuality and future fertility - those are really big conversations to have at 10. So the idea with puberty blockers is that you don't have to have all of those conversations at that age."

International comparisons

New Zealand guidelines followed the World Professional Association for Transgender Health, which recommended blockers for children with "persistent and well documented gender dysphoria".

In contrast, several European countries, including Sweden, Finland, France, England and Wales, and Denmark have signalled moves to restrict access to blockers, because of uncertainty about the natural course of gender dysphoria, a lack of evidence about long-term benefits and harms.

In March, Britain's' National Health Service banned the routine use of puberty blockers after a four-year investigation by leading paediatrician Dr Hilary Cass concluded there was "not enough evidence to support their safety or clinical effectiveness".

Her report also found nearly all those children and young people prescribed puberty blockers subsequently went on to cross-sex hormones.

Clinicians were "unable to determine with any certainty" which children and young people would go on to have an enduring trans identity, therefore a medical pathway was not the best way to manage gender-related distress for most.

Surgeons have also pointed out blockers have made gender-affirming surgery more difficult as there is less tissue available if pubertal development is frozen.

The New Zealand study showed that up until 2020, use in this country was up to seven times higher than England and Wales and 1.7 times higher than the Netherlands, which pioneered the use of blockers to treat gender dysphoria in the 1990s, the so-called 'Dutch Protocol'.

Paediatric endocrinologist Paul Hofman - who reviewed the paper prior to publication - said it was difficult to make international comparisons because there was only data from individual clinics in other countries, and the Pharmac data did not show why the drugs were prescribed.

"Even with these caveats these data are concerning - we may be prescribing substantively more pubertal suppressive therapy than two European countries," he said.

"Given this is an expensive therapy and the evidence for its efficacy in transgender youth remains relatively weak, it suggests that Pharmac should ask for a transgender diagnostic category for pubertal suppressive therapy use to confirm its prevalence in New Zealand.

"While the study cannot categorically demonstrate increased pubertal suppressive therapy use in New Zealand, it raises an important question that needs answering."

The levelling off and subsequent 20 percent decline in use over the last two or three years was "interesting", he said.

"If this plateauing/ decrease persists it is unclear whether this reflects a saturated market, a changing approach by physicians treating transgender youth, or concerns about the safety of use."

High prescribing rates 'a good sign' - gender-affirming clinicians

The Professional Association for Transgender Healthcare Aotearoa has not responded to RNZ's request for its response.

One of its executive members, Dr Rona Carroll, was not available for interview - but in a written statement to media, said it was "not surprising" that New Zealand had higher rates of prescribing puberty blockers because it offered better access to appropriate, holistic care.

"New Zealand is a progressive country which recognises the importance of accessibility to healthcare and support for gender diverse young people.

"Our model of care is different from the centralised gender clinic model used in the comparison countries in this paper. These centralised clinics overseas have often led to excessively long wait times for care."

The higher prescribing rates were "a good sign" that young people felt safe expressing their gender and health needs, and had access to services, she said.

Meanwhile, the Ministry of Health has yet to release its own evidence brief on blockers along with a guide for clinicians, which was originally set to be made public late last year.