Abstract
A gestational sac implanted in the anterior portion of the lower uterine segment is characteristic of a cesarean delivery scar pregnancy, although it is the rarest of locations for an ectopic pregnancy. More common locations for an ectopic pregnancy include the isthmus of the tube, ovaries, uterine cornua, and abdomen. In addition to sonographic diagnosis, elevated serum beta-human chorionic gonadotropin levels can help to confirm the pregnancy. If detected early, a future pregnancy may be possible; otherwise, the patient is at risk for uterine scar rupture, hemorrhage, and maternal morbidity. Ectopic pregnancies are becoming more prevalent, although it is difficult to say if it is due to an increase in cesarean sections performed, the use of in vitro fertilization procedures, or better diagnosis and documentation. This case illustrates implantation of a pregnancy within the scar of a previous cesarean section delivery, diagnosed with pelvic, endovaginal, and 3D sonography.