Editing Pearl Index (section)

== Usage ==
The Pearl Index is sometimes used as a statistical estimation of the number of [[unintended pregnancy|unintended pregnancies]] in 100 woman-years of exposure (e.g. 100 women over one year of use, or 10 women over 10 years). It is also sometimes used to compare birth control methods, a lower Pearl index representing a lower chance of getting unintentionally pregnant.<ref>{{Cite web |title=Birth control failure rates - the Pearl Index explained |url=https://www.drugs.com/medical-answers/birth-control-failure-rates-pearl-index-explained-3554953/ |access-date=2023-12-19 |website=Drugs.com |language=en}}</ref>

Usually two Pearl Indexes are published from studies of birth control methods:<ref>{{Cite web |title=Muvs - Der Pearl-Index |url=https://muvs.org/en/topics/contraception/the-pearl-index/ |access-date=2023-12-19 |website=muvs.org |language=en}}</ref>
* the ''actual use'' Pearl Index, which includes all pregnancies in a study and all months (or cycles) of exposure
* the ''perfect use'' or ''method'' Pearl Index, which includes only pregnancies that resulted from correct and consistent use of the method, and only includes months or cycles in which the method was correctly and consistently used