​Citations and Impact Factor

Citation data are an important part of evaluating a scientific journal. Below, we provide data on metrics used by Obstetrics & Gynecology as well as tools for readers available on our web site.


In June of each year, several metrics using citation data are released to publishers and scientific journals. One well-known metric is the impact factor, which is "a measure of the frequency with which the 'average article' in a journal has been cited in a particular year or period."1

Obstetrics & Gynecology's 2016 impact factor is 5.426. The journal's ranking is the third highest impact factor out of all 80 obstetrics and gynecology journals. Five-year history is available in the Table.

 Year  Impact Factor  Ranking
2016  5.426 3rd of 80 journals
2nd of 80 journals
2nd of 79 journals
  4.368 3rd of 78 journals
2012   4.798 2nd of 77 journals

The 5-year impact factor is the average number of times articles from the journal published in the past 5 years have been cited in a particular year.2 Obstetrics & Gynecology’s 2016 5-year impact factor is 5.871.

The immediacy index is the average number of times an article is cited in the year it is published.2 Obstetrics & Gynecology’s 2016 immediacy index is 1.343.

The Eigenfactor score is a calculation based on the number of times articles from the journal published in the past five years have been cited in [a particular] year, but it also considers which journals have contributed these citations so that highly cited journals will influence the network more than lesser cited journals. References from one article in a journal to another article from the same journal are removed, so that Eigenfactor Scores are not influenced by journal self-citation.2 Obstetrics & Gynecology’s 2016 Eigenfactor score is 0.05584.

For more information on the impact factor, see Benner RS. Evaluating the importance of a journal: the impact factor and other metrics. Obstet Gynecol 2012;119:3–4.

Web Site Tools

The Obstetrics & Gynecology web site features tools that will make tracking important research easy:

  1. Alert Me When Cited allows registered users to receive an e-mail alert every time an article is cited by another article. To take advantage of this feature, simply look in the “Article Tools” box on the right side of the screen when viewing an article at GreenJournal.org.
  2. Cited By is a list of articles that have cited a given article, and can be found at the end of the full-text HTML version of an article, following its reference list. Hyperlinks in the Cited By list enable you to link out to PubMed and locate the article on the web via CrossRef functionality.
  3. Highest Impact articles are identified at Greenjournal.org in addition to the most viewed and most e-mailed articles. A special filter is employed to detect articles with rapid citation activity (articles that have been cited more quickly than the average article). The result is a list of what are often key papers in the field.


  1. Clarivate Analytics. The Thomson Reuters Impact Factor. Available at: http://wokinfo.com/essays/impact-factor/. Retrieved June 20, 2017.
  2. Thomson Reuters. InCites Help. Glossary. Available at: http://ipscience-help.thomsonreuters.com/incitesLive/glossaryGroup/glossaryOnePageFull.html. Retrieved June 20, 2017.