THE number of WA children seeking to transition to the opposite sex has jumped more than 350 per cent in four years.

Perth Children’s Hospital’s gender diversity service received 121 referrals for children aged under 18 in 2017-18 and currently has 207 patients in the service.

This compares to 116 referrals in 2016-17 and 105 in 2015-16. The steady increase over the past three years compares with just 26 referrals in 2014-15.

About two-thirds of current referrals are birth-assigned females and about one-third are birth-assigned males.

At the moment, there are 43 children receiving stage one hormonal treatment, which involves puberty suppression and reversible treatment, while 30 children are receiving stage two cross-sex hormone, oestrogen and testosterone treatment.

The rising number of transgender children comes as the WA’s Law Reform Commission recommends an overhaul of the State’s gender reassignment laws.

As revealed by The Sunday Times last month, the commission has recommended a baby’s sex classification no longer appears on birth certificates.

Under the changes, people would no longer have to undergo a medical procedure to have their gender identity officially recognised. Instead they would just apply for a “proof of gender’ or “proof of sex” certificate.

There would be three categories on these certificates — male, female and a new category of “non-binary”. Under the recommendations, minors aged 12 or over could seek a certificate to formally change their gender.

If they didn’t have permission of both parents, the Family Court would decide.

Moves to change gender classification laws come amid social media backlash to a recent tweet by Prime Minister Scott Morrison that said: “We do not need ‘gender whisperers’ in our schools. Let kids be kids.”

The PM was responding to moves by schools to invite specialist consultants to offer support to transgender students and their families.

WA’s Gender Reassignment Board’s latest annual report shows there were 34 new applications last year, compared with just six in 2007-08.

A spokeswoman for the Child and Adolescent Health Service said PCH’s gender diversity service provided “assessment and care of children and adolescents experiencing gender diversity issues”.

“Any child or young person up to the age of 18, who lives in WA, can be referred to the GDS for consultation about concerns regarding their gender identity, gender non-conforming behaviour or gender dysphoria,” the spokeswoman said.

“Gender dysphoria refers to the distress that a person may experience when their gender identity does not align with the sex assigned to them at birth.”

She said the service started midway through the 2014-15 financial year and only provided services intermittently.