Previous history of an ectopic pregnancy, pelvic infections caused by STD's, taking medication to stimulate ovulation or in-vitro fertilization treatments, pregnancy when using an intrauterine device (IUD) or after tubal ligation, previous surgery involving your fallopian tubes or structural concerns and smoking shortly before pregnancy can cause ectopic pregnancy.
Ectopic pregnancy is a complication of pregnancy in which the embryo attaches outside the uterus. Most often, ectopic pregnancy happens within the first few weeks of pregnancy. Up to an estimated 20 in every 1,000 pregnancies are ectopic.
Risk Factors of Ectopic Pregnancy:
Previous Ectopic Pregnancy – The greatest risk factor for this type of a pregnancy is a previous history of such pregnancy. If you’ve had one ectopic pregnancy, you’re more likely to have another.
Infection in the Pelvis (pelvic inflammatory disease) – Pelvic infections are another risk factor for ectopic pregnancy, and are usually caused by sexually-transmitted organisms, such as Chlamydia or N. gonorrhoeae. However, non-sexually transmitted bacteria can also cause pelvic infection and increase the risk of such a pregnancy.
Fertility Treatments – Taking medication to stimulate ovulation (the release of an egg) can increase the risk of ectopic pregnancy by around four-fold. The type of fertility treatment such as in-vitro fertilisation (IVF) may not always be successful and can accidentally result in an ectopic pregnancy.
Contraceptive Choice – Pregnancy when using an intrauterine device (IUD) is rare. If pregnancy occurs, however, it’s more likely to be ectopic, similarly for pregnancy after tubal ligation (a permanent method of birth control).
Smoking – Cigarette smoking just before you get pregnant can increase the risk of an ectopic pregnancy. And the more you smoke, the greater the risk.
Previous Surgery and Structural Concerns – A surgery involving your fallopian tubes, increases the risk of having an ectopic pregnancy. Even surgery to reconstruct the fallopian tube can increase the risk. An ectopic pregnancy is also more probable if you have an unusually shaped fallopian tube.