Wolf G C, Thompson N J
Obstet Gynecol. 1980 Jan;55(1):17-9.
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.
对俄亥俄州代顿市都会区1970年1月至1977年12月进行了一项为期8年的回顾性研究。在此期间，共有86,809例分娩和721例输卵管妊娠。其中33例异位妊娠发生在先前接受过输卵管绝育术的患者中。过去4年中7.4%的发生率（393例中的29例）表明先前绝育术作为异位妊娠病因的重要性日益增加。
