Abstract
BACKGROUND: Interstitial pregnancies are rare and often difficult to diagnose given their proximal position to the uterine cavity, however most are identified by 12 weeks gestation. Delayed or missed diagnosis contributes to heightened incidence of poor outcomes including hemorrhage and death. CASE PRESENTATION: A 35-year-old woman at 15 weeks gestation with confirmed intrauterine pregnancy on first trimester ultrasound and prior negative MRI presented in hemorrhagic shock and was found to have a ruptured interstitial pregnancy. Exploratory laparotomy revealed the fetus to be in the abdomen as well as a large cornual defect and abnormal placentation that resulted in supracervical hysterectomy. CONCLUSIONS: Interstitial pregnancy should be considered in a patient presenting with symptoms consistent with ectopic rupture, especially in the setting of equivocal or suboptimal prior imaging. Earlier diagnosis may allow for fertility-sparing intervention and decreased risk of morbidity and mortality.