In this radiology lecture, we discuss the ultrasound appearance of ruptured ectopic pregnancy. Key points include: * Most ectopic pregnancies occur in the fallopian tube: Ampulla most common, followed by isthmus and fimbria. * Risk factors: Prior ectopic pregnancy, prior surgery (fallopian tube), pelvic inflammatory disease, endometriosis, IVF. * “A single measurement of hCG, regardless of its level, does not reliably distinguish between ectopic and intrauterine pregnancy (viable or nonviable).”* * Levels of hCG in ectopic pregnancies are highly variable. * Tubal rupture main complication, occurs in up to 20%. * Free fluid in pelvis alone nonspecific, but echogenic fluid in Morison pouch (subhepatic space) and cul-de-sac raises concern for rupture. * Rupture is a relative contraindication to methotrexate (medical) therapy. *Doubilet PM, Benson CB, Bourne T, et al. Diagnostic criteria for nonviable pregnancy early in the first trimester. N Engl J Med 2013;369:1443-51.