An ectopic pregnancy is when implantation of the gestational sac occurs outside of the uterus. The most common location for an ectopic pregnancy is the fallopian tubes. It can also occur in the interstitial or cornual portion of the uterus (2%), intraabdominally (1.5%), on the ovary (0.1%)and or within the cervix (0.1%). A history of a previous ectopic pregnancy is regarded as the greatest risk factor. Also previous tubal surgery and in utero diethylstilbestrol (DES) exposure.