Definition: Intersex is a general term used for conditions in which a person is both with reproductive or sexual anatomy that does not fit typical definitions of male or female. This may or may not be visibly noticeable, and does not always show up right away.

Facts:

• There are over fifteen known intersex conditions.
• At medical centers, a child is born so noticeably atypical in terms of genitalia that a specialist in sex differentiation is called in about 1 in 1500 to 1 in 2000 births.
• Below we provide a summary of statistics drawn from an article by Brown University researcher Anne Fausto-Sterling:
  
  • Not XX and not XY: one in 1,666 births
  • Klinefelter (XXY): one in 1,000 births
  • Classical congenital adrenal hyperplasia: one in 13,000 births
  • Late onset adrenal hyperplasia: one in 66 individuals
  • Vaginal agenesis: one in 6,000 births
  • Ovotestes: one in 83,000 births
  • Hypospadias (urethral opening in perineum or along penile shaft): one in 2,000 births
  • Hypospadias (urethral opening between corona and tip of glans penis): one in 770 births
  • Total number of people whose bodies differ from standard male or female: one in 100 births
  • Total number of people receiving surgery to "normalize" genital appearance: one or two in 1,000 births

Issues:

• There is no defining line between typical and atypical sex variation, so there is no agreement about which conditions are considered intersex. In general, doctors decide who counts as intersex at birth.
• Doctors routinely perform unnecessary and potentially harmful operations to differentiate the sex of an intersex baby without fully disclosing the condition nor the possible ramifications of an operation to the baby's parents.
• Although most intersex conditions are benign, some forms of intersex signal underlying metabolic concerns. A person who thinks he or she might be intersex should seek a diagnosis and find out if he or she needs to seek out professional care.
• The word "hermaphrodite" is stigmatizing and misleading. Unfortunately, some medical personnel still use this outdated term to refer to people with certain intersex conditions. 

Important information for allies:

• Be informed.

• Use proper terminology, for example use the word intersex not hermaphrodite.

• Remember that a person’s biological status is personal. You do not have the right to know it, and should not ask about it. If a person chooses to share with you, receive it as a gift, in confidence, and do not share it with others.

Sources: http://www.isna.org/