First, do no harm.

Four simple words taught early and often in medical school. Words to live by, and practice by, we’re taught. But can we? Is it possible? After all, almost everything we do as physicians carries some risk of harm. It may be minor as in the pain after successful surgery. It can be life-altering or even life-threatening as in our failure to report a suspicion of child maltreatment for a variety of truly inconsequential reasons.

Bear with me though as I present a current controversy with respect to children not adults. Keep an open mind and reflect deeply on those four words.

Let’s begin, though, with something non-controversial.

When is the human brain fully mature? Socrates knew it to be the mid-20s, as did Shakespeare. Science waited until the late 20th Century to declare correct these observant men. This was an important admission since it made clear that children, even through their adolescent years, don’t have the mental capacity to make long-term, life-altering decisions. That’s why parents consent to have their children receive needed surgery, unpleasant cancer chemotherapy, and the like.

Now the controversy, chosen because it surfaces almost daily in the media and in the halls of medicine. I write of the transgender issue.

First, do no harm! While it’s always been true, and non-controversial, that little boys sometimes dress in girls’ clothes, and little girls sometimes would rather play with trucks than dolls, it has never before meant that their sex designation was wrong. Another non-controversy is that chromosomes determine sex and they are unalterable. A child can no more make him or herself someone of the opposite sex than they could become chimpanzees.

Moreover, these feelings are transient and, if not supported and/or encouraged, extinguish by late adolescence. That’s why the American Psychiatric Association calls this (for the present at least) “gender dysphoria”, a treatable mental health condition.

But children’s brains are plastic and can be molded by experience, by parents dressing them as the opposite sex, calling them an opposite sex name, and insisting that all others do the same. They become, in their brains, the sex others create for them.

First, do no harm! Hanne Gaby Odiele, a true intersex person, speaks forcefully about the harmful physical and emotional effects of the surgical procedures physicians told her were necessary. Her advocacy work encourages therapy and peer support rather than medical and surgical treatment that is often irreversible and sometimes unnecessary.

How much truer this is for the otherwise simply questioning child. Yet we increasingly seem to have no qualms about accepting the decisions of a child incapable of making those decisions. We also seem to support media and political (non-medical) imperatives to accept these immature decisions. And so we prescribe, or send children to colleagues who prescribe, puberty blocking hormones, followed by medications to modify secondary sex characteristics, followed by surgery, all for a condition which usually (90+%) cures itself by late adolescence (though some children, and their families, will require counselling in the interim).

When children refuse potentially life-saving chemotherapy we take them or their parents to court. When an adolescent is anorexic, believes him or herself to be overweight, or suffers from a similar body image problem, we counsel rather than prescribe appetite suppressants. When a family refuses immunizations we discharge them from our practices. When parents want growth hormone or anabolic steroids prescribed so their child can be (more) competitive in the child’s favourite sport, we refuse.

We do what is best for the patient even if it displeases them or family. It’s imperative then that we treat the transgender thinking child in the same way.

Puberty is a normal, natural occurrence. Puberty-blocking drugs create an abnormal condition. Cross-sex hormones (testosterone and estrogen) are associated with health risks including high blood pressure, blood clots, stroke, and cancer. In addition, rates of suicide are 20 times greater among adults who've used cross- sex hormones and/or have undergone sex reassignment surgery, even in Sweden which is among the most transgender-affirming countries.

So we arrive at a crossroads. Do we stand firm in the practice of medicine or do we follow the crowd? Endorsing sex reassignment for children as normal in our offices, or via the media and public policy, will inevitably lead more children to puberty-blocking drugs. This, in turn, virtually ensures they will “choose” a lifetime of carcinogenic and toxic cross-sex hormones, and likely consider surgical mutilation of their healthy body parts -- all to avoid perhaps some counselling, parental support for their genetic sex, and a period of watchful waiting.

First, do no harm! Think about it.

Joseph Zanga, MD, FCP is a founder and past president of the American College of Pediatricians.