A 27-year-old has just had an ectopic pregnancy. Which of the following events would be most likely to predispose to ectopic pregnancy?

Any factor delaying transit of the ovum through the fallopian tube may predispose a patient to ectopic pregnancy. The major predisposing factor in the development of ectopic pregnancy is pelvic inflammatory disease. However, any operative procedure on the fallopian tubes may increase a patient's risk. It appears that tubal sterilizations with laparoscopic fulguration have a higher rate of ectopic pregnancy than tubal ligations performed with clips or rings. Women who have had one ectopic pregnancy are at increased risk of having a second. DES exposure, induction of ovulation, and IUD use increase the possibility of ectopic pregnancy