Ectopic pregnancy more commonly affects women who have a number of related conditions. A partial list of factors that have been tied to ectopic pregnancy include:
- becoming pregnant while using an intrauterine device (IUD) for contraception
- contracting sexually transmitted diseases (STDs)
- tubal ligation when the fallopian tubes have been tied to prevent conception
- endometriosis, a condition in which tissue that should grow only in the uterus grows in other areas
- in vitro fertilization
- a prior history of ectopic pregnancy
Age may be a related condition of ectopic pregnancy as there is a higher reported incidence among women older than 35 and younger than 20. There also is a higher risk for sexually active women who have been intimate with many different partners.
Ectopic pregnancy is occasionally misdiagnosed as pelvic inflammatory disease (PID), another related condition which is caused by sexually transmitted infections such as chlamydia and gonorrhea and has similar symptoms. PID may lead to ectopic pregnancy because it can create scars on the fallopian tubes, known to sometimes block the fertilized egg from moving into the uterus.