Causes
If you've had an infection in the pelvic region (e.g., pelvic inflammatory
disease) or pelvic surgery, or were born with a medical condition that narrowed
your fallopian tubes, you have a greater chance of having an ectopic pregnancy.
A previous ectopic pregnancy can also increase your risk of a second ectopic
pregnancy. An unsuccessful tubal ligation, a sterilization procedure in which
the fallopian tubes are cut or blocked, can contribute to the risk of an ectopic
pregnancy.
Ectopic pregnancies have also been linked to the use progesterone-only birth
control pills, and the morning-after pill. Women who use IUDs, especially those
containing progesterone, have a higher risk of having an ectopic pregnancy if
they do become pregnant despite using the IUD. Women who were exposed to a medication
called diethylstilbestrol* (a synthetic estrogen) in their mother's womb are
also at greater risk of ectopic pregnancy.