What is intersex?

Intersex means that someone was born with sex characteristics that do not fully fit the usual male or female pattern. These characteristics may involve chromosomes, hormones, gonads or sex organs. Doctors usually use the term DSD, an abbreviation for Differences of Sex Development.

What does intersex mean?

Intersex is an umbrella term, not a diagnosis. The word covers a range of different congenital variations in sex development. The term DSD was established in 2006 in an international consensus statement by doctors. At the time, the abbreviation stood for Disorders of Sex Development. Today, the word Disorders is increasingly being replaced by Differences.

Intersex says something about the body. It says nothing about someone's sexual orientation and is different from being transgender. Examples of variations considered intersex or DSD include:

• Klinefelter syndrome (XXY): chromosomally male, with varying physical effects;
• Turner syndrome (X0): chromosomally female, with effects on growth and fertility;
• Congenital adrenal hyperplasia (CAH): excessive production of androgens, particularly relevant in children with XX chromosomes;
• Androgen insensitivity syndrome (AIS): the body of someone with XY chromosomes does not respond, or responds less, to androgens;
• 5-alpha-reductase deficiency: the external male sex organs develop differently from usual.

What is an intersex person?

An intersex person is someone with one of these congenital variations. Most intersex people live as men or women and see themselves that way too. Some regard their variation as part of who they are and speak openly about it. Others see it as a medical fact that does not need to play a role in their identity. Both views occur. Being intersex does not make someone transgender or non-binary.

What does intersex look like?

Usually, there is nothing visible from the outside. Many variations involve chromosomes, hormones or internal organs. Such a variation is not always discovered at birth. Sometimes it only becomes apparent during puberty, for example when puberty develops differently than expected. You cannot tell from someone's appearance or clothing whether they are intersex.

What do the sex organs of an intersex person look like?

That differs depending on the variation. In many intersex people, the external sex organs look typically male or female. In a small proportion of children, it is not immediately clear at birth whether the external sex organs are male or female. Doctors then refer to this as ambiguous genitalia. It is estimated to occur in 1 in 2,000 to 4,500 births. There is therefore no single intersex appearance.

Intersex baby: what parents are told

Sometimes a midwife or doctor is uncertain about a child's sex, either at birth or during an ultrasound scan in pregnancy. The child is then referred to a DSD team at an academic hospital. Such a team may include a paediatric endocrinologist, paediatric urologist, gynaecologist and social worker. The Radboudumc expertise centre tells parents that a variation in external sex characteristics is not in itself an illness and that most children have a good start in life. However, ambiguous genitalia can indicate an illness or a disrupted hormone balance. That is why investigations are carried out promptly.

The paediatrician performs a physical examination. Blood is taken to determine, among other things, hormone levels. A paediatric radiologist performs an ultrasound of the internal organs, kidneys and sex organs. Genetic testing may be carried out if necessary. According to Radboudumc, most tests are completed within three days.

There is a legal provision for registering a birth. If the sex is uncertain, the birth certificate states that the sex could not be determined. A new certificate is issued within three months based on a medical statement. For more information about a later amendment, see changing sex registration.

Surgery in intersex children

Not every variation requires surgery. Sometimes there is a medical reason to operate. For a long time, young children were also operated on without medical necessity, to make their bodies fit the sex registered at birth. Intersex organisations and human rights bodies, including the United Nations, have criticised this practice as a violation of bodily integrity because the child cannot give consent. In the Netherlands, the guidelines have been tightened to favour a more cautious approach. There is not yet a legal ban.

How many people are intersex?

That depends strongly on the definition. The often-cited figure of 1.7 percent comes from biologist Anne Fausto-Sterling. She included all variations that differ from the usual pattern. Most of that 1.7 percent consists of a late-onset, mild form of CAH. In 2002, doctor Leonard Sax counted only cases in which chromosomal sex does not correspond to external sex, or in which the body cannot be classified as male or female. He arrived at approximately 0.018 percent. That is fewer than two in every ten thousand births. Klinefelter syndrome and Turner syndrome, among others, fall outside Sax's definition. When reading a figure, it is therefore important to check which definition it is based on.

Is intersex a third sex?

No. In public debate, intersex is often cited as evidence that biological sex is a spectrum. That reasoning is controversial. Human reproduction is based on two types of sex cells: sperm cells and egg cells. There is no third type. DSDs are variations in development towards one of the two and do not constitute an additional sex. The full argument is set out in the article Intersex is not a third sex. For more background, see gender and biological sex.

Intersex and transgender are often mentioned together, but they have little to do with each other in substance. Intersex concerns the body. Transgender concerns gender identity, or how someone sees themselves. The abbreviations AMAB and AFAB refer to the sex registered at birth. With intersex children, that registration is sometimes uncertain. The difference and overlap between the two are explained in more detail at transgenderidentiteit.nl.