Female sterilization and subsequent ectopic pregnancy.

An 8-year retrospective study was conducted of the metropolitan Dayton, Ohio, area from January 1970 through December 1977. During this period of time there were 86,809 births and 721 tubal pregnancies. Thirty-three of the ectopic pregnancies were in patients who had previously undergone a tubal sterilization. The 7.4% rate (29 of 393) in the past 4 years indicates the increasing importance of previous sterilization as an etiologic agent in ectopic gestation.