Final answer:
Risk factors for ectopic pregnancy include endometriosis, pelvic inflammatory disease (PID), previous history, infertility treatments, and lifestyle factors like smoking and older age.
Step-by-step explanation:
Ectopic pregnancies, particularly tubal pregnancies, occur when an embryo implants outside the uterus and can have several risk factors besides scar tissue from a sexually transmitted infection. Risk factors include endometriosis, pelvic inflammatory disease (PID), history of ectopic pregnancy, infertility treatments, and certain lifestyle factors like smoking and older age. Endometriosis can cause structural problems in the Fallopian tubes, increasing the risk of ectopic implantation, while PID often results from sexually transmitted infections like gonorrhea and chlamydia, which can lead to scarring and blockages. Furthermore, treatments for infertility, including in vitro fertilization, may inadvertently increase the risk of an ectopic pregnancy. Lastly, lifestyle factors such as tobacco smoking, excessive alcohol consumption, and being either overweight or underweight are also associated with an increased risk of developing an ectopic pregnancy.