Ectopic Pregnancy

Abstract

Ectopic pregnancy, the implantation of a fertilized ovum outside the uterine cavity, has been increasing in number at a staggering pace and now accounts for 2% of all pregnancies in the United States. Since many ectopic pregnancies are now treated in an outpatient setting, true current numbers are hard to obtain. Nearly all ectopic pregnancies (97%) are implanted within the fallopian tube, and a common factor for the development of such ectopics is the presence of a pathological fallopian tube. Ectopic implantation can also occur outside of the fallopian tube: within the cervix, ovary, abdomen, uterine cornua, cesarean scars, and anywhere within the peritoneal cavity. These extratubal implantations may not be associated with tubal pathology or the expected preexisting risk factors for tubal ectopic implantation. The imaging modality of choice for the diagnosis of early pregnancy, regardless of implantation site, is transvaginal ultrasound.