Objective: The purpose of this article is to review key clinical issues and imaging features of unusual pregnancy implantations. Examples from different imaging modalities are provided to increase interpreting physicians' familiarity with the appearance and potential complications of unusual ectopic, cesarean scar, heterotopic, and rudimentary horn pregnancies.
Conclusion: Abnormal pregnancy implantations are life-threatening. Interpreting physicians' familiarity with the appearance of unusual pregnancy implantations is critical for early identification and initiation of appropriate therapy.
Keywords: abdominal ectopic pregnancy; cervical ectopic pregnancy; cesarean scar pregnancy; heterotopic pregnancy; interstitial ectopic pregnancy; ovarian ectopic pregnancy; rudimentary horn pregnancy.