Skip to content

Intersex – the background


Share on facebook
Share on twitter
Share on linkedin
Share on whatsapp

Most of us consider sex as a black or white issue. You are either male or female. But the truth is not as simple as that. The development of sexual characteristis lies on a spectrum. The arbitrary terms of male or female are a human definition rather than a natural one. A person may be born appearing to be mostly male on the outside but with female-typical anatomy on the inside. They may be born with genitalia that seem to fall in between norms e.g. a boy with a very small penis or divided scrotum with appearance of labia. Or they may be born with mosaic genetics so that some cells comprise of XX chromosomes and some XY. Intersex may be apparent at birth but it is often not until puberty, or occasionally later into adulthood via infertility clinics, that it becomes manifest.

Eve emerging from Adam's rib - Saint Ambrose, Hexaemeron - Germany 12th Century

Intersex does away with the myth of the  gender binary as classically depicted by Adam and Eve. Perhaps it is also better to move away from the term “normal” to describe genitalia. One German study looked at a group of 500 men and found that urologists would only label 55% as ‘normal’ according to medical standards. 225 of the 500 had a degree of hypospadias. This makes the idea that the tip of the glans is the normal spot for the urethra to open questionable.

The Australian Human Rights Commission in Surgery on Intersex Infants and Human Rights (2009) uses the term ‘intersex’ as an umbrella term to describe people who are not born, or do not develop, as exclusively male or female

The formation of usual reproductive anatomy

Intersex is distinct from sex, sexual orientation or gender identity. To simplify things it is worthwhile considering the development of normal reproductive anatomy. Seven weeks after conception the internal and external embryonic genitalia are identical. This excellent video from Armando Hasudungan may make things more clear.

Biological sex is determined by many things then – the  number and type of sex chromosomes, the presence of ovaries or testes, sex hormones, internal reproductive anatomy and what we see on the outside. A change in any of these may characterize someone as intersex.

Just to clarify some basic terms:-

Gender What someone feels like and identifies with
Sex What some looks like physically – male, female or intersex
Sexuality What someone is attracted to


How common is it?

With a wide variety of potential definitions it is hard to determine how common intersex is. If you just include children with obviously atypical genitalia then the figure is about 1 in 1500 to 1 in 2000 live births. Some conditions, such as congenital adrenal hyperplasia or androgen insensitivity syndrome may lead to ambiguous genitalia from birth. Some may only be evident due to failure of usual puberty and some, such as hypospadias, may be misdiagnosed as non-intersex conditions. Less conservative estimates place intersex as occurring in around 1.7% of live births. To put this in context, the incidence of red hair at birth is between 1 and 2%.  In 2008 a voluntary registry, the I-DSD was set up to help improve data capture.

What sort of conditions may lead to intersex?

  • 5 α reducatase deficiency
  • Androgen Insensitivity Syndrome (AIS)
  • Aphallia
  • Clitoromegaly
  • Coongenital Adrenal Hyperplasia
  • Gonadal Dysgenesis (complete or partial)
  • Hypospadias
  • Klinefelter’s Syndrome
  • Micropenis
  • Clitoromegaly
  • Sex Chromosome mosaicism
  • MRKH (Mayer-Rokitansky-Küster-Hauser sundrome orMullerian agenesis)
  • Ovo-testes (true hermaphroditism)
  • Partial Androgen Insensitivity Syndrome
  • Progestin Induced Virilization
  • Swyer Syndrome
  • Turner Syndrome

What is DSD?

In 2006 a group of clinicians in Chicago replaced the term intersex with “Disorders of Sexual Development”, or DSD, in the “Summary of Consensus Statement on Intersex Disorders and Their Management”. The concern is that this term reinforced the idea that being intersex is a disorder that needs to be fixed rather than a normal variant and returned to a more paternalistic model of care rather than one that encompassed shared decision making. Some of the community prefer the term intersex as a term that promotes equality and decreases marginalisation.  One must consider that intersex activists may represent the vocal minority. Other terms used include differences of sex development and variances of sex development.

DSD and the DSM

The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 2013) also renames intersex as a Disorder of Sexual Development and a subset of Gender Dysphoria. This reclassification increases, rather than decreases as was the aim, the risk of stigmatisation and marginalisation.



Support and Advocacy

Organisation Intersex International Australia

Intersex UK



Filipas D, Mottrie AM, Voges GE, Hohenfellner R. Analysis of meatal location in 500 men: wide variation questions need for meatal advancement in all pediatric anterior hypospadias cases. The Journal of urology. 1995 Aug 31;154(2):833-4.

Blackless M, Charuvastra A, Derryck A, Fausto-Sterling A, Lauzanne K, Lee E. How sexually dimorphic are we? Review and synthesis. American Journal of Human Biology. 2000 Mar 1;12(2):151-66.

Hughes IA, Houk C, Ahmed SF, Lee PA, Society LW. Consensus statement on management of intersex disorders. Journal of pediatric urology. 2006 Jun 30;2(3):148-62. 

Hutson JM, Warne GL, Grover SR, editors. Disorders of sex development: an integrated approach to management. Springer Science & Business Media; 2012 Feb 2.

About the authors


High flow therapy – when and how?

Chest compressions in traumatic cardiac arrest

Searching for sepsis

The missing link? Children and transmission of SARS-CoV-2

Don’t Forget the Brain Busters – Round 2

An evidence summary of Paediatric COVID-19 literature


The fidget spinner craze – the good, the bad and the ugly

Parenteral Nutrition

Leave a Reply

Your email address will not be published.



We use cookies to give you the best online experience and enable us to deliver the DFTB content you want to see. For more information, read our full privacy policy here.