What does trans mean and what is the Cass Review?

The rights of transgender or trans people - and whether they affect the rights of women - are often in the spotlight.

This has led to legal disputes, protests and discussions about free speech.

In a landmark independent review of gender identity services for under-18s, a leading clinician said children were being let down by a lack of research on medical interventions in gender care.

Gender identity is a term used by some to describe someone's sense of their gender. A transgender person's gender identity is not the same as the sex recorded on their original birth certificate.

A transgender man is someone registered female at birth, but who identifies as a man.

A transgender woman is someone registered male at birth, but who identifies as a woman.

Trans is a shorter way of saying transgender.

Gender dysphoria describes the "unease or dissatisfaction" some people feel about the difference between their biological sex and gender identity.

Some people who do not consider themselves to have a solely male or female gender identity describe themselves as non-binary.

A child's sex is recorded as male or female at birth, based on physical characteristics.

Some people are born with chromosomal or other physical differences that can make this a complex judgement. They are sometimes referred to as intersex, or having differences of sexual development (DSD).

In the 2021 census, 262,000 people aged 16 and over in England and Wales said their gender identity was different to their birth sex.

Some academics raised concerns that the question may not have been understood, and that number could be an overestimate.

The Office for National Statistics (ONS) said it cannot be certain if that is the case, but the results were accurately processed and are broadly consistent with other estimates.

A 2018 estimate by the government suggested there could be between 200,000 and 500,000 people who identify as transgender across the UK as a whole.

Many transgender people live according to their chosen gender identity - including how they dress, and the name and pronouns they use.

Some may take hormone medication, or have surgery.

People can also apply to alter the gender listed on official documents.

These social, physical and legal changes are known as transitioning.

Under the Gender Recognition Act 2004, UK adults can get a gender recognition certificate (GRC) if they meet certain criteria:

This means their acquired gender can be recorded on their birth, marriage and death certificates.

You do not need a GRC to update your driving licence, passport or medical records.

However, non-binary is not recognised as a gender on legal documents in the UK.

About 7,000 certificates have been issued in England, Wales and Scotland.

The Cass Review is an independent report into gender identity services for under-18s, commissioned by NHS England.

Led by paediatrician Dr Hilary Cass, the landmark document said children have been "let down" by the lack of reliable evidence on medicine for those questioning their gender.

It called for gender services for young people to match the standards of other NHS care.

Dr Cass said clinicians had been worried about having "no guidance, no evidence, no training" and that the "toxicity" of the debate around gender meant professionals were "afraid" to openly discuss their views.

The report made 32 recommendations on how future services should operate.

NHS England said it has already made significant progress in making changes and a review into adult services will also be conducted.

The Gender Identity and Development Service (Gids) was the the only NHS gender clinic for children in England and Wales.

It provided assessments of young people with gender-related distress and was able to refer them for medical treatment and to provide support.

It closed in March 2024, after a Care Quality Commission (CQC) inspection in late 2020 rated it "inadequate".

Inspectors found problems with record-keeping, inconsistencies in clinician's approaches, and poor leadership.

Its closure was announced in 2022, shortly after Dr Cass published an interim report into Gids which said having a single specialist provider was "not a safe or viable long-term option".

In April 2024 a new service known as the NHS Children and Young People's Gender Service opened.

It has two regional hubs - one in the North West, led by Alder Hey Children's Hospital, and one in London, led by Great Ormond Street Children's Hospital.

NHS England says it plans to open six hubs, offering services for people up to their 18th birthday.

It says they will offer support with physical and mental health, as well as the emotional, psychological and social aspects of gender identity.

The services are yet to offer appointments to the thousands of patients on the waiting list.

They will see those patients who were under the care of Gids first.

NHS England says young people will start to be transferred to the northern hub "as soon as appointments become available", and to the London hub "later in 2024".

Internal emails leaked to the BBC showed staff had voiced concerns over the safety of the transfer to new services.

Different services are available in other parts of the UK.

Young people in Scotland can get a GP referral or refer themselves to the gender service at the Sandyford clinic.

Those in Northern Ireland who want to talk to a specialist about their gender identity can use the Knowing Our Identity service.

In Wales, children or teenagers can be referred or refer themselves to a specialist Gender Identity Clinic (GIC).

In January 2024, a private hormone clinic for transgender young people became the first in the UK to receive approval from the CQC.

An NHS document released in March 2024 said that the new services will be able to prescribe cross-sex hormones, mainly in the form of testosterone or oestrogen.

Also known as gender-affirming hormones, NHS England will only prescribe them to patients who meet certain criteria from "around their 16th birthday".

In Scotland, they are only available to those over the age of 18 until further research is carried out.

Some transgender people take cross-sex hormones to help change their physical characteristics and relieve distress about their body not aligning with their gender identity.

The NHS says their long-term use may have some side effects - including blood clots, weight gain, acne and hair loss - and that they can cause infertility.

The Cass Review warned that under-18s should only be prescribed cross-sex hormones under "extreme caution", and only when there was a "clear clinical rationale" for doing so.

Puberty supressing hormones - better known as puberty blockers - are no longer routinely prescribed by NHS England for children whose gender identity is causing them distress.

A review by NHS England found there wasn't enough evidence to prove they were "safe or effective."

This was echoed in the Cass Review, which also recommended more research into the long-term outcomes of patients who receive puberty blockers.

New puberty blocker prescriptions for gender-distressed children are now only recommend as part of clinical trials. Details of these trials are yet to be confirmed.

Following Dr Cass's review, Scotland's only gender identity clinic for under-18s also paused new prescriptions of blockers until further research is done.

Puberty blockers are described by the NHS as a way to delay or supress the physical changes of puberty, such as the development of breasts, facial hair or Adam's apples.

There are currently fewer than 100 children in England on puberty blockers prescribed by the NHS. They will be able to continue to take them.

Under Department for Education (DFE) guidance issued in December 2023, teachers in England should tell parents if their child wants to change their gender identity at school.

The Gender Questioning Guidance - which is not compulsory - says this should happen in the "vast majority of cases".

In rare circumstances, teachers can decide to withhold information if revealing it could put a child at "significant risk" of harm.

Schools should also "take a very cautious approach" if pupils want to use a new name, pronouns or uniform.

Non-statutory guidance was issued to Northern Irish schools in 2019, and to Scottish schools in 2021. The Welsh government has not yet published guidance.

There has been much debate about how to balance the rights of different groups within society.

Much of this has focused on access to women-only spaces such as toilets, domestic abuse refuges and prisons.

There has also been controversy about the participation of trans women in female-only categories in sports.

Transgender people may wish to use services and facilities which align with their gender identity, whereas other groups say that these should be separated by birth sex.

The Equality Act 2010 identifies a number of groups with protected characteristics - including gender reassignment and sex - and protects those groups from discrimination.

But single-sex service providers can exclude transgender people where this is a ''proportionate means of achieving a legitimate aim'', such as privacy or safety.

However, some say the law is not clearly understood and women's sex-based rights are under threat.

The Equality and Human Rights Commission suggests that amending the Equality Act definition of "sex" to "biological sex" is worth further consideration.

This would make it simpler for certain spaces to be single-sex, regardless of whether a person has a GRC.

The UK government is considering the advice.