title: Histologic development of cervical ectopy: relationship to reproductive hormones.
abstract: OBJECTIVE
  Cervical ectopy has been proposed as a risk factor for chlamydial infection, HIV, and other sexually transmitted diseases (STDs). Ectopy is a histologic phenomenon resulting from a complex interplay of morphologic and hormonal processes. Reproductive hormones influence the production of ectopy during late fetal life, puberty, pregnancy, and with use of oral contraceptives. Ectopy is modified over time by squamous metaplasia and epitheliazation, low pH, trauma, and possibly by cervical infection.
  
  
  METHODS
  The authors review the histologic development of ectopy from late fetal life to menopause to understand STD risk.
  
  
  RESULTS
  Ectopy is often assessed and quantified by direct, unaided observation during speculum examinations. This method may result in inaccurate estimates and misclassification with the transformation zone.
  
  
  CONCLUSIONS
  Valid, reproducible measures of ectopy are necessary for epidemiologic studies to examine the impact of exogenous hormonal contraceptives on the development of ectopy and on potential infection risk.
authors.affiliation: Department of Epidemiology, Johns Hopkins School of Public Health, Baltimore, Maryland, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Jacobson
authors.forename: L
authors.initials: L
authors.lastname: Peralta
authors.forename: N M
authors.initials: NM
authors.lastname: Graham
authors.forename: J
authors.initials: J
authors.lastname: Zenilman
mesh_terms: D000293:Adolescent; D000328:Adult; D002584:Cervix Uteri / Q000002:abnormalities / Q000187:drug effects / Q000473:pathology*; D003276:Contraceptives, Oral / Q000494:pharmacology; D004848:Epithelium / Q000187:drug effects / Q000473:pathology; D005260:Female; D012739:Gonadal Steroid Hormones / Q000494:pharmacology*; D006801:Humans; D008875:Middle Aged; D011247:Pregnancy
chemical_list: D003276:Contraceptives, Oral; D012739:Gonadal Steroid Hormones