Intersex variations

What intersex means

Intersex is an umbrella term for people born with sex characteristics — chromosomes, gonads, hormones or genital anatomy — that do not fit typical binary definitions of male or female. It is a description of bodies, not of gender identity or sexual orientation. Most intersex people identify as men or women; some do not.

Blackless et al. (2000, American Journal of Human Biology) estimated that around 1.7 percent of people have some intersex trait under a broad definition. Narrower clinical definitions, which exclude late-onset congenital adrenal hyperplasia and common chromosomal variations, give figures nearer 0.02–0.05 percent. Both numbers are widely cited; the difference is definitional, not a dispute about the underlying data.

Common variations

• Androgen insensitivity syndrome (AIS): XY chromosomes with partial or complete inability to respond to androgens. Complete AIS typically produces typical female external anatomy, a shorter vagina, and no uterus. Incidence around 1 in 20,000–64,000 births.
• Congenital adrenal hyperplasia (CAH): an enzyme deficiency, usually 21-hydroxylase, causing prenatal androgen exposure in XX individuals and variable genital development. Classic CAH occurs in roughly 1 in 14,000–18,000 births and has significant medical management needs beyond sex characteristics.
• Klinefelter syndrome (47,XXY): around 1 in 500–1,000 births assigned male; often associated with lower testosterone and reduced fertility.
• Turner syndrome (45,X): around 1 in 2,000–2,500 births assigned female; associated with ovarian insufficiency and cardiac considerations.
• 5-alpha-reductase deficiency, gonadal dysgenesis, ovotesticular variation, MRKH (Müllerian agenesis, absent or underdeveloped uterus and upper vagina, around 1 in 4,500) and others.

Surgery on intersex infants

Non-consensual, medically non-urgent surgery on intersex infants is the central ethical issue in this field. Long-term outcome data are limited but consistently unfavourable on the measures studied: reduced genital sensation, need for repeat surgery, urethral stricture, scarring, dyspareunia, and psychological harm including PTSD symptoms. Studies of clitoral surgery outcomes (Crouch et al., 2008; Minto et al., 2003) found significantly impaired sexual function in operated groups.

Since 2013 the UN Special Rapporteur on Torture, the WHO, the Council of Europe, Physicians for Human Rights and multiple national bodies have called for deferral of non-urgent, irreversible procedures until the person can consent. Malta (2015), Portugal, Germany, Iceland, Greece and Spain have enacted legal restrictions. Surgery that treats genuine medical urgency — obstructed urinary flow, salt-wasting CAH crisis, gonadal cancer risk with real evidence behind it — is a different matter and is not what these bodies object to.

Intimacy in practice

Intersex variation affects intimacy in specific, individual ways: vaginal length or depth, lubrication, hormone-dependent sensation, surgical scarring, hair distribution, fertility, and — often most significantly — the effects of medical secrecy and repeated childhood genital examination.

• Vaginal length varies; some people use dilation, some prefer positions with shallower depth, some avoid vaginal penetration entirely. Dilation should be self-directed and never coerced; coerced dilation in adolescence is reported as traumatic.
• Lubrication may be reduced after gonadectomy or where hormone levels are low. Lubricant and, where clinically appropriate, topical oestrogen help.
• Scar tissue can be less elastic and differently sensitive. Slower approach, changed angles and adequate lubricant matter more than usual.
• Hormone therapy, where a person is on it because gonads were removed or do not function, affects libido, tissue quality and mood. Dose and route are worth revisiting with an endocrinologist if sexual function changes.
• Fertility varies by variation and by surgical history; assumptions in either direction are unsafe.

Disclosure

There is no obligation to disclose an intersex variation to a partner. Many people do choose to, particularly where anatomy or fertility is directly relevant. Disclosure works best on the discloser's timing, in a private and unhurried setting, with only the detail the person wants to share. Being intersex is not an STI risk, a deception, or a medical warning that requires announcement.

Sources

• Blackless M et al. "How sexually dimorphic are we? Review and synthesis." American Journal of Human Biology, 2000.
• Sax L. "How common is intersex? A response to Anne Fausto-Sterling." Journal of Sex Research, 2002.
• Crouch NS et al. "Sexual function and genital sensitivity following feminizing genitoplasty for congenital adrenal hyperplasia." Journal of Urology, 2008.
• Minto CL et al. "The effect of clitoral surgery on sexual outcome in individuals with ambiguous genitalia." Lancet, 2003.
• Lee PA et al. "Global Disorders of Sex Development Update since 2006." Hormone Research in Paediatrics, 2016.
• UN Special Rapporteur on Torture, A/HRC/22/53, 2013; WHO et al. "Eliminating forced, coercive and otherwise involuntary sterilization," 2014.
• interACT and Human Rights Watch. "I Want to Be Like Nature Made Me." 2017.

Last reviewed: August 2026.