Author: Jared Scott, MD Educational Pearls: Data is mixed, but some studies show 1-2% of pregnancies are ectopic. Risk factors for ectopic pregnancies include: pelvic inflammatory disease, prior ectopic pregnancy, prior abdominal surgery, prior abortion, advanced maternal age, IUD, tubal blockage, and smoking (including spouse). Greatest risk factor is a prior ectopic pregnancy, which carries a 17x higher risk. Patients with histories of PID and cigarette smoking present educational opportunities.   References Moini, A., Hosseini, R., Jahangiri, N., Shiva, M., & Akhoond, M. R. (2014). Risk factors for ectopic pregnancy: A case–control study. Journal of Research in Medical Sciences : The Official Journal of Isfahan University of Medical Sciences, 19(9), 844–849. Rana, P; Kazmi, I; Singh, R; Afzal, M; Al-Abbasi, FA; Aseeri, A; Singh, R; Khan, R; Anwar, F (2013). "Ectopic pregnancy: a review". Archives of Gynecology and Obstetrics. 288 (4): 747–57. doi: 10.1007/s00404-013-2929-2.