Intersex

“Intersex” is an umbrella term for differences in sex development (DSD). People born with these differences have features that aren’t typically male or female. These differences can involve:

• Chromosomes
• Hormones
• Reproductive organs
• Genitals

Some intersex traits are noticeable at birth. You might not see others until puberty. In some cases, you may never notice physical differences. You may only learn that you have an intersex trait when you’re getting tested for an unrelated reason.

Healthcare providers often use the term “differences of sex development (DSD)” when talking about intersex conditions. You may also see the term “disorders of sex development.” DSD describes a group of conditions with a wide range of features and health effects. Some people prefer the term intersex, while others prefer DSD.

How common is intersex?

Estimates vary. This depends on how healthcare providers define and diagnose intersex conditions. One study suggests disorders of sex development occur in about 1 out of every 2,700 births. Older estimates included conditions that providers don’t always count as intersex.

What does intersex mean?

Having an intersex condition typically means there’s a mismatch between your external genitalia appearance and characteristic features of your expected gender, defined by chromosomes, hormones and internal reproductive organs.

Intersex traits are usually present at birth. Being intersex can appear in many ways. No two people’s bodies are exactly alike. Intersex differences can involve chromosomes, hormones, reproductive organs or genitals.

Chromosomes

Most people have sex chromosomes that are typically male (XY) or female (XX). People who are intersex may have:

• A mix of cells with different chromosomes (mosaicism)
• Extra chromosomes (like XXY)
• Only one X chromosome (XO)
• Other, less common combinations

Hormones

Intersex conditions can involve differences in how your body produces or responds to sex hormones. These include testosterone and estrogen. These differences may affect puberty and development.

Reproductive organs

Some intersex people have both ovaries and testicles. This is called ovotestes. Others have a mix of internal organs. They have some that are typically male and some that are typically female.

Genitals

Genital traits can vary widely. Someone may have external body parts typical of one sex and internal parts typical of the other. Other people may have differences in clitoris size or a penis with impaired testicle development.

What causes being intersex?

Experts don’t always know why people are born with intersex traits. Some conditions are passed down through biological families. Others happen due to changes in genes during fetal development. These include:

• Changes in the androgen hormone receptor gene
• Differences in the SRY gene

Hormone levels during development can also affect how reproductive organs and sex characteristics develop.

There are chemicals in the environment called endocrine-disrupting chemicals (EDCs). EDCs can also interfere with hormone function and cause intersex.

Does being intersex affect sexual orientation?

Being intersex doesn’t determine sexual orientation. Intersex people may be straight, gay, lesbian, bisexual or another sexual identity. Intersex traits are about biological differences. They’re not about who you’re attracted to.

Is a person who is intersex a hermaphrodite?

No. The term “hermaphrodite” is outdated and misleading. Most intersex people consider the term offensive. Using terms like “intersex” or “differences of sex development” are more accurate and respectful.

What health conditions are linked to being intersex?

Some intersex traits are linked to health conditions that need medical attention. These include:

• Chromosomal changes: These include syndromes like Klinefelter syndrome (XXY) and Turner syndrome (XO).
• Hormonal differences: These are conditions like congenital adrenal hyperplasia and androgen insensitivity syndrome.
• Atypical genitalia: This includes conditions like hypospadias and Mayer-Rokitansky-Küster-Hauser syndrome.

Does being intersex affect fertility?

Fertility depends on your body. Some intersex people get pregnant naturally. Others may need to use assisted reproductive technology. These include:

• In vitro fertilization (IVF)
• Donated eggs, sperm or embryos
• Gestational carriers (surrogates)

How do I know if I’m intersex?

You may not notice intersex traits at birth. Some people learn later in life through:

• Delayed puberty
• Puberty changes that don’t match your assigned sex
• Infertility or trouble getting pregnant

If you have any concerns, talk to a healthcare provider.