Sex assignment (also known as gender assignment[1][2]) is the discernment of an infant's sex, typically made at birth based on an examination of the baby's external genitalia by a healthcare provider such as a midwife, nurse, or physician.[3] In the vast majority of cases (99.95%), sex is assigned unambiguously at birth. However, in about 1 in 2000 births, the baby's genitalia may not clearly indicate male or female, necessitating additional diagnostic steps, and deferring sex assignment.[4][5]
In most countries the healthcare provider's determination, along with other details of the birth, is by law recorded on an official document and submitted to the government for later issuance of a birth certificate and for other legal purposes.[6]
The prevalence of intersex conditions, where a baby's sex characteristics do not conform strictly to typical definitions of male or female, ranges between 0.018% and 1.7%.[7][8][9] While some intersex conditions result in genital ambiguity (approximately 0.02% to 0.05% of births[4]), others present genitalia that are distinctly male or female, which may delay the recognition of an intersex condition until later in life.[10][11]
Societally and medically, it is generally assumed that a person's gender identity will align with the sex assigned at birth, making them cisgender. However, for a notable minority, assigned sex and gender identity do not coincide, leading to transgender identity experiences. When assigning sex to intersex individuals, some healthcare providers may consider the gender identity that most people with a similar intersex condition develop, although such assignments may be revised as the individual matures.[2][12]
The use of surgical or hormonal interventions to reinforce sex assignments in intersex individuals without informed consent is considered a violation of human rights, according to the Office of the United Nations High Commissioner for Human Rights.[13][2][14][15]
^"Intersex population figures". Intersex Human Rights Australia. 16 September 2019 [28 September 2013]. Archived from the original on 17 July 2018. Retrieved 3 July 2023.