Sexual development is determined by chromosomes during fertilization. In the early stages of human development, a human embryo has the precursors of female (paramesonephric or Müllerian ducts) and male (mesonephric ducts or Wolffian) gonads.[2] If a Y chromosome is lacking, or defective as seen in Swyer syndrome, the embryo will reabsorb the mesonephric ducts and proceed with paramesonephric ducts, which give rise to ovaries. The Y chromosome contains a sex-determining region called the SRY gene. Thus, the developmental plan of the embryo is altered only if this gene is present and functional.[3]
Mutations affecting the androgen receptor (AR) gene may cause either complete or partial androgen insensitivity syndrome. Androgens are a group of hormones which regulate the development and maintenance of male characteristics. Between 8 and 12 weeks, human male fetuses become externally distinct as androgens enlarge the phallus and produce a penis with a urethra and scrotum.[4]
Female pseudohermaphroditism refers to an individual with ovaries and external genitalia resembling those of a male. Male pseudohermaphroditism refers to an individual with testicles and external genitalia resembling those of a female.[5][6] In some cases, external sex organs associated with pseudohermaphroditism appear intermediate between a typical clitoris and penis. Thus, pseudohermaphroditism is sometimes not identified until puberty or adulthood.
Persistent Müllerian duct syndrome was considered a form of pseudohermaphroditism, developed through Müllerian-inhibiting factor defects. In such instances, duct derivatives are present in males, including the uterus, fallopian tubes, and upper vagina.[7]
Surgery is sometimes performed to alter the appearance of the genitals. Sex-specific cancers present on the gonads may require surgical removal.[8][9][10][11]
The term "Pseudohermaphroditimus" (pseudohermaphroditism) was coined in German by Edwin Klebs in 1876.[16][17] Klebs had included the term as a synonym for the earlier coined, "spurious hermaphroditism" (which he referred to as Schein-Zwitter in German).[17] "Spurious hermaphroditism" was coined in 1836 by J. Y. Simpson.[18]
Although "pseudohermaphroditism" persisted in the International Classification of Diseases, Versions 9 (ICD-9) and 10 (ICD-10) as 752.7 (Indeterminate sex and pseudohermaphroditism)[19] and Q56 (Interdeterminate sex and pseudohermaphroditism),[20] it has since been removed in the eleventh version (ICD-11), in favor of LD2A.Y (Other specified malformative disorders of sex development).[21]
Some experts have indicated that both pseudohermaphroditism (also called false hermaphroditism) and true hermaphroditism are outdated,[22][23][24][25][26][27] confusing,[24][28] and potentially pejorative terms,[24][27][28][29][30] indicating replacement with "disorders of sex development", "disorders of sexual development", "differences of sex development" (all abbreviated as DSD)[22][24][27] or "intersex".[23][30]
Additionally, intersex activists have noted that: "The qualifiers 'pseudo' and 'true' are even more harmful [than hermaphrodite on its own], because they imply a sort of authenticity, or lack of same, that carry powerful emotional baggage".[31] Dreger et al had also noted that "division of many intersex types into true hermaphroditism, male pseudohermaphroditism, and female pseudohermaphroditism is scientifically specious and clinically problematic".[32]
Quattrin T, Aronica S, Mazur T (December 1990). "Management of male pseudohermaphroditism: a case report spanning twenty-one years". Journal of Pediatric Psychology. 15 (6): 699–709. doi:10.1093/jpepsy/15.6.699. PMID 2283575. Hughes IA, Williams DM, Batch JA, Patterson MN (1992). "Male pseudohermaphroditism: clinical management, diagnosis and treatment". Hormone Research. 38 (2): 77–81. doi:10.1159/000182604. PMID 1292987. Klebs, T. A. E. (1876). Handbuch der pathologischen Anatomie [Handbook of pathological anatomy]. Berlin: A. Hirschwald, p. 723. Simpson, J. Y. (1836). "Hermaphroditism" in The Cyclopaedia of Anatomy and Physiology. Vol. 2. p. 685. Amato V (2016). Intersex Narratives: Shifts in the Representation of Intersex Lives in North American Literature and Popular Culture. Bielefeld: Transcript Verlag. ISBN 978-3-8394-3419-2. Hughes IA (February 2008). "Disorders of sex development: a new definition and classification". Best Practice & Research. Clinical Endocrinology & Metabolism. 22 (1): 119–134. doi:10.1016/j.beem.2007.11.001. PMID 18279784. Houk CP, Hughes IA, Ahmed SF, Lee PA (August 2006). "Summary of consensus statement on intersex disorders and their management. International Intersex Consensus Conference". Pediatrics. 118 (2): 753–757. doi:10.1542/peds.2006-0737. PMID 16882833. S2CID 46508895. Dreger AD, Chase C, Sousa A, Gruppuso PA, Frader J (August 2005). "Changing the nomenclature/taxonomy for intersex: a scientific and clinical rationale". Journal of Pediatric Endocrinology & Metabolism. 18 (8): 729–733. doi:10.1515/jpem.2005.18.8.729. PMID 16200837. S2CID 39459050.