The Prader scale or Prader staging, named after Dr. Andrea Prader, is a coarse rating system for the measurement of the degree of virilization of the genitalia of the human body[1][2] and is similar to the Quigley scale. It primarily relates to virilization of the female genitalia in cases of congenital adrenal hyperplasia (CAH) and identifies five distinct stages, but in recent times has been used to describe the range of differentiation of genitalia, with normal infant presentation being shown on either end of the scale, female on the left (0) and male on the right (6).[3]



While the scale has been defined as a grading system for "abnormal" genitalia,[2] the concept that atypical genitals are necessarily abnormal is contested. An opinion paper by the Swiss National Advisory Centre for Biomedical Ethics advises that "not infrequently" variations from sex norms may not be pathological or require medical treatment.[8] Similarly, an Australian Senate Committee report on involuntary sterilization determined that research "regarding 'adequate' or 'normal' genitals, particularly for women, raises some disturbing questions", including preferences influenced by doctors' specialism and gender.[9]

Related concepts

Numerous clinical scales and measurement systems exist to define genitals as normal male or female, or "abnormal", including the orchidometer, Quigley scale and the satirical Phall-O-Meter.[citation needed]

See also


  1. ^ White PC, Speiser PW; Speiser (June 2000). "Congenital adrenal hyperplasia due to 21-hydroxylase deficiency". Endocr. Rev. 21 (3): 245–91. doi:10.1210/edrv.21.3.0398. PMID 10857554.
  2. ^ a b Prader, Andreas (1954). "Der genitalbefund beim pseudohermaphroditismus femininus der kengenitalen adrenogenitalen syndroms". Helv. Paedialr. Ada. 9: 231–248.
  3. ^ "Figure 1: The Prader Scale. Top: schematic representation of the..." ResearchGate. Retrieved 2017-06-13.
  4. ^ a b c d Harris, Wayne (2006). Examination Paediatrics : a Guide to Paediatric Training (3rd ed.). Sydney: Churchill Livingstone Elsevier. pp. 132–134. ISBN 978-0729537728.
  5. ^ Diamond, Milton; Linda Ann Watson (2004). "Androgen insensitivity syndrome and Klinefelter's syndrome: sex and gender considerations". J. Child Adolesc Psychiatric Clin N Am. 13 (3): 623–640. doi:10.1016/j.chc.2004.02.015. PMID 15183377. Archived from the original on 2006-12-14.
  6. ^ Ogilvy-Stuart, AL; Brain, CE (May 2004). "Early assessment of ambiguous genitalia". Arch Dis Child. 89 (5): 401–7. doi:10.1136/adc.2002.011312. PMC 1719899. PMID 15102623.
  7. ^ Hutson, John M.; Warne, Garry L.; Grover, Sonia R. (2012). Disorders of Sex Development : An Integrated Approach to Management. Berlin: Springer. p. 105. ISBN 978-3642229633.
  8. ^ Swiss National Advisory Commission on Biomedical Ethics NEK-CNE (November 2012). On the management of differences of sex development. Ethical issues relating to "intersexuality".Opinion No. 20/2012 (PDF). 2012. Berne. Archived from the original (PDF) on 2015-04-23.
  9. ^ Australia (2013). Involuntary or coerced sterilisation of intersex people in Australia. Canberra: Community Affairs References Committee. ISBN 9781742299174.