Also known as genital ambiguity or intersex.


 What is genital ambiguity?

For some newborns, it is not possible to tell whether the child is a boy or a girl, based on outward appearance. With others, the genitals may be partially masculinised or feminised. More subtle (and common) anatomical variations such as small penis, undescended testes or hypospadias in boys, or enlarged clitoris or labia in girls, can be considered mild forms in the spectrum of ambiguous genitalia.


 What causes this?

Ambiguous genitalia are most often caused by elevated exposure of the XX fetus to male sex hormones (eg. congenital adrenal hyperplasia, CAH), or reduced sensitivity of the XY fetus to male sex hormones (eg, partial androgen insensitivity syndrome). In some cases the causes of ambiguous genitalia are anomalies in the genetic networks that direct gonadal development, in a large and varied group of disorders called gonadal dysgenesis. In those disorders, any genetic or environmental event that compromises the ability of the developing gonads to produce the right types or the right amounts of the critical hormones may result in incomplete masculinisation or feminisation of the external genitals.


 How common is it?

Genital ambiguity occurs approximately once in every 4500 live births.


 Is it a cause for concern?

Inability to designate a person as male or female may have some practical, psychological, ethical and even legal issues, and, depending on circumstances, may come with medical and/or reproductive complications.

In some cases, such as CAH, the situation may be life-threatening, not because of the effects on the sex organs but because hormones that are essential for maintaining electrolyte balance and other metabolic functions are severely deficient. The possibility of CAH means that immediate testing is necessary.

Ambiguous genitalia may also be a symptom of a genetic disorder that has more widespread effects in the body. Many inherited genetic syndromes are associated with genital ambiguity.

Aside from these cases, the ambiguous genitalia themselves do not present an acute medical emergency. Lack of clearly defined maleness or femaleness may become an issue of confusion, embarrassment, or trauma as the child grows and develops an awareness of gender, requiring ongoing care and sensitivity from parents and carers. Depending on the cause, fertility may be reduced later in life, and some intersex conditions are associated with increased risk of gonadal cancers if untreated.


 What is usually done about it?

In more pronounced cases of genital ambiguity, it is difficult to determine from a simple inspection whether the phallus is a small penis or a large clitoris, or whether the genital skin folds are swollen labia or an incompletely formed scrotum. In some cases the testes, if present, may remain in the abdomen, instead of descending into the scrotum as they usually do in males. Therefore, imaging (such as ultrasound or MRI) is usually done to determine whether gonads are present or absent, and whether they are ovaries, testes, ovotestes, or a mixture of gonadal types. Imaging also reveals what other internal sex organs are present. Hormonal tests are used to determine, among other things, whether testosterone levels are consistent with the presence of functioning testes, and whether certain endocrine pathways are blocked, as in CAH. Tests will almost certainly be carried out to assess what sex chromosomes are present (XX, XY or something else). A rapid molecular test for the presence of the Y chromosome takes half a day; a full karyotype analysis takes several days. Finally, a number of genetic tests can be carried out to look for specific gene defects. The results of these tests are important in helping to decide a course of action.

Medical management of children with ambiguous genitals is usually complex and long-term.

It may involve performing "gender assignment" surgery to make the external genitals more male-like or female-like, and/or treating with hormones that encourage a less ambiguous path of sex development.

Alternatively, it may be that not doing anything, or delaying a decision on whether and how to intervene surgically until the child is old enough to understand the sutuation and contribute to discussions and decisions, is considered more preferable.

Arguments in support of gender assignment surgery on infants with ambiguous genitals include:

  • If surgery is ever to be performed, it can be advantageous to perform it as early as possible when tissues respond better to restructuring;
  • Early surgery will not traumatise the child through the memory of the surgery;
  • As techniques improve, the probability that sexual function can be maintained is greater than in previous decades.

If surgery is undertaken, long-term treatment with the appropriate hormones is usually prescribed to bring all aspects of sex-specific development into line with the genital sex. Similarly, support is provided to monitor the appearance and function of the genitals until puberty and beyond. Ongoing counselling, physiotherapy and/or occupational therapy are likely to be required.

An alternative option is to leave the genitals as they are, leave options open, and wait until the child grows to a stage where their situation can be discussed with them and they can participate in decision-making.

Arguments in support of not intervening surgically, and leaving options open include:

  • There is no medical emergency: Typically the child is not ill and their life is not in danger;
  • Important decisions should not be rushed;
  • It makes some sense to delay any possible surgery until it becomes obvious whether the child is identifying as a boy or as a girl;
  • The person affected should be involved in the decision rather than having others, including parents, make important decisions on their behalf.

These days, the growing trend is to not intervene during infancy. In this case the affected person may benefit from long-term support from counsellors, social workers and intersex support groups.

Clearly, important decisions need to be made, and all information, advice and options should be carefully weighed. This may involve considering medical, social, and legal issues and receiving advice from medical professionals and intersex advocacy groups.

Medically, each case is normally referred to a specialist team at a children’s hospital. This team will normally include pediatricians, social workers and counsellors, who can provide specific diagnostic details for each child, advise on the likely prognosis, and discuss available medical options, including the option not to intervene or to leave options open.

Some information relating to living and coping with intersex, and legal and ethical issues around intersex, can be found under Other sources of information.

Readers are advised to seek the services of a qualified medical practitioner when considering any diagnosis or treatment options. See Disclaimer.



Last updated: 6 August 2021 PK

Edit history: Author P. Koopman 9/2009; revised PK 5/2011, 9/2012, 3/2013, 5/2013, 10/2013, 7/2015