title: Citation classics in obstetrics and gynecology: the 100 most frequently cited journal articles in the last 50 years.
abstract: OBJECTIVE
  Our objective was to characterize the most frequently cited articles published in obstetrics and gynecology journals during the last 50 years.
  
  
  METHODS
  We utilized the 2008 edition of Journal Citation Reports and Social Sciences Citation Index database to determine the most frequently cited articles published after 1956. Articles were evaluated for several characteristics, and an unadjusted categorical analysis was performed to compare pre- and post-1980 articles.
  
  
  RESULTS
  The 100 most frequently cited articles were published in 11 journals between 1957 and 2004. Most articles were published by US-based authors. Forty-four articles were related to obstetrics and 56 were related to gynecology. The most common study design was observational. There were only 7 randomized controlled trials, and randomized controlled trials were not more common after 1980 (6.3% vs 8.1%; P = .71).
  
  
  CONCLUSIONS
  Most "citation classics" in obstetrics and gynecology are observational studies published in high-impact journals by US-based authors after 1980.
authors.affiliation: Department of Obstetrics and Gynecology, New York Presbyterian Hospital-Weill Cornell Medical Center, New York, NY 10021, USA.
authors.forename: Justin S
authors.initials: JS
authors.lastname: Brandt
authors.forename: Amy C
authors.initials: AC
authors.lastname: Downing
authors.forename: David L
authors.initials: DL
authors.lastname: Howard
authors.forename: Jason D
authors.initials: JD
authors.lastname: Kofinas
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Chasen
mesh_terms: D015706:Bibliometrics; D016206:Databases, Bibliographic; D006176:Gynecology; D006801:Humans; D055811:Journal Impact Factor; D009774:Obstetrics; D010506:Periodicals as Topic / Q000706:statistics & numerical data*; D011642:Publications / Q000706:statistics & numerical data*; D012107:Research Design