What Canadian doctors say about new U.K. review questioning puberty blockers for transgender youth

A long-anticipated — and contentious — national review of gender-affirming care for youth in England was released last week, resulting in headlines across the U.K. saying that gender medicine is "built on shaky foundations."

The Cass Review, chaired by pediatrician Hilary Cass, was commissioned by England's National Health Service (NHS) in 2020. 

Even before the final report was published, the review has led to significant changes for youth gender medicine in England, where the debate over transgender care has become increasingly heated, with complaints of both long waiting lists and medical treatments being too readily available to youth.

Last month, the Cass Review findings led to a ban on the prescription of puberty-suppressing hormones except for youth enrolled in clinical research.

That's a move away from the standard of care supported by many international medical bodies, including the Canadian Pediatric Society (CPS), the American Academy of Pediatrics and World Professional Association for Transgender Health. Though several European countries including Sweden have also restricted access to puberty blockers and other medical treatments for youth.

The report cites a systematic review of evidence, commissioned as part of the Cass Review, which found "a lack of high-quality research" that puberty blockers can help young people with gender dysphoria.

While experts in the field say more studies should be done, Canadian doctors who spoke to CBC News disagree with the finding that there isn't enough evidence puberty blockers can help.

"There actually is a lot of evidence, just not in the form of randomized clinical trials," said Dr. Jake Donaldson, a family physician in Calgary who treats transgender patients, including prescribing puberty blockers and hormone therapy in some cases.

"That would be kind of like saying for a pregnant woman, since we lacked randomized clinical trials for the care of people in pregnancy, we're not going to provide care for you.… It's completely unethical."

When evaluating a drug or treatment, the question is always: how safe and effective is it? 

"Puberty blockers have been used for decades for precocious puberty," or very early onset of puberty, said Dr. Sam Wong, president of the pediatrics section with the Alberta Medical Association.

"There are side effects with every medication, and I would talk [with patients and their families] about the side effects, but for the most part it's a safe medication."

Puberty blockers slow or pause the effects of hormones a young person's body produces — for example, delaying the onset of a menstrual period or physical changes like breast growth, a lowered voice, or growth of the Adam's apple. 

Their effects are considered reversible. When the medication stops, puberty resumes.