Answer 5:

Damage to the Fallopian tube by infection surgery, prior ectopic, or postoperative adhesion formation has been reported to increase ectopic rates to as high as 27%. A history of salpingitis is obtained for 30% to 50% of women operated on for ectopic pr egnancy. Conception after elective tubal sterilization can increase the ectopic risk to 60% depending on the technique used. Prolonged IUD use is associated with increased risk. Also when "the morning after pill" fails to interrupt pregnancy a 10-fold incr ease of ectopic pregnancy has been reported. Patients exposed to diethylstilbestrol (DES) in utero have a 5% to 13% risk of ectopic gestation.

{Ref. Danforth's Obstetrics and Gynecology, 7th edition, pp. 187-189.}