Healthdirect Free Australian health advice you can count on.

Medical problem? Call 1800 022 222. If you need urgent medical help, call triple zero immediately

healthdirect Australia is a free service where you can talk to a nurse or doctor who can help you know what to do.

beginning of content

Intersex variation

5-minute read

Key facts

  • People born with ‘intersex variations’ have characteristics that don’t fit the typical definition of a female or male body.
  • Intersex variation can be physical, hormonal or chromosome-related.
  • Intersex variation occurs in an estimated 1 in every 100 births.
  • Surgery for intersex variation is not recommended until a child is old enough to make an informed decision for themselves.

On this page

What does ‘intersex’ mean?

People born with intersex variations have physical characteristics that don't fit the usual definition of a female or male body.

The term 'intersex' refers to a wide spectrum of variations to genitals, hormones, chromosomes and/or reproductive organs.

Some people with intersex variations may, for example, have typical sexual characteristics of a female on the outside, but mostly male-typical anatomy on the inside. A person might be born without a uterus, or with a micropenis. A person's genitals might be ambiguous ('in between' the typical features of a male and female). These are just a few examples.

Intersex variation can also include 'mosaic genetics', which means a person has cells that have XX (female) chromosomes as well as XY (male) chromosomes. Or, they might have an atypical combination of chromosomes, such as XXY.

Some genetic conditions involve intersex anatomy, including Klinefelter syndrome and Turner syndrome.

Back to top

How common is intersex variation?

It’s difficult to say how prevalent intersex variations are since medical professionals don’t always agree on what counts as intersex. Also, many people are born with variations that don’t show up until puberty or adulthood.

However, intersex variation is a natural biological event that has been estimated to occur in about 1 in every 100 births.

Back to top

What causes intersex variation?

In the first few weeks after conception, genitals in a fetus develop in the same way, regardless of whether the baby is a male or female. At week 7, the genitals start to develop in line with the sex of the fetus, under the influence of hormones.

An imbalance of hormones, or an inability of the fetus to respond to the hormones, can result in an intersex variation.

Back to top

How is gender assigned in people with intersex variation?

It is recommended that a child be assigned a gender soon after birth, based on the gender they are most likely to identify with as they grow up. This does not involve surgery and is not to be confused with gender confirmation surgery (previously known as ‘gender reassignment’ ).

If you're a parent of an intersex child, it's OK to delay announcing the gender and name of your child until you are ready. For more information and support, visit Intersex Human Rights Australia.

Back to top

Does intersex variation need treatment?

Being intersex is not a health issue in itself and is considered a normal biological event.

Unless a person needs urgent medical attention after birth or treatment for specific health concerns related to intersex variation, such as infertility, medical intervention is not normally necessary.

Surgery for intersex variation is not recommended (or even necessary) until a child is old enough to make an informed decision for themselves.

Children and adults with intersex variation, and their parents, may benefit from counselling and support.

Back to top

Are people with intersex variation transgender?

Intersex variation is not the same as transgender, which is where a person identifies as a gender that is different from the biological sex they were assigned at birth.

An intersex person may identify as female, male or neither, straight, gay, lesbian, bisexual or asexual.

However, Australian research shows that people with intersex variation are more likely to be non-heterosexual than people in the general population. About half of people with intersex variation are heterosexual (straight).

Back to top

Resources and support

Learn more here about the development and quality assurance of healthdirect content.

Last reviewed: December 2019

Back To Top

Need more information?

These trusted information partners have more on this topic.

Top results

Supporting an intersex teenager - ReachOut Parents

Here's your guide to supporting an intersex teenager. If you're wondering what it means to be intersex and how you can support, visit for more info.

Read more on website

Lesbian, gay, bi, trans, intersex (LGBTI), bodily, gender and sexuality diverse people

LGBTI people's experiences with discrimination and stigmatisation can lead to a higher likelihood of emotional distress, depression and anxiety

Read more on Beyond Blue website

Understanding what it means to be intersex | ReachOut Australia

Here's your introductory guide to understanding intersex people and the challenges they may face day to day.

Read more on website

Healthdirect 24hr 7 days a week hotline

24 hour health advice you can count on

1800 022 222

Government Accredited with over 140 information partners

We are a government-funded service, providing quality, approved health information and advice

Australian Government, health department logo ACT Government logo New South Wales government, health department logo Northen Territory Government logo Government of South Australia, health department logo Tasmanian government logo Government of Western Australia, health department logo