Diagnostic and Therapeutic Challenges in Rare and Non-Tubal Ectopic Pregnancies: A Narrative Review

In relation to the most commonly described ampullary ectopic pregnancies in contemporary gynecological practice, rare localizations of ectopic pregnancies represent a diagnostic and therapeutic challenge whose clinical significance far exceeds their frequency. In contrast to tubal ectopic pregnancy, these implantation localizations are characterized by specific anatomical relationships and early trophoblastic invasion into highly vascularized tissues, which is why classical diagnostic algorithms and therapeutic patterns are often not applicable in clinical practice. Clinical uncertainty is further increased by the fact that a large proportion of these pregnancies in early gestation cannot be precisely mapped and initially present as pregnancies of unknown location. This narrative review integrates contemporary evidence and guidelines of relevant professional societies with the aim of highlighting patterns of diagnostic errors, systemic weaknesses of existing approaches, and key points for safe clinical decision-making. Special emphasis is placed on the role of disciplined transvaginal ultrasound evaluation, terminological precision, and timely recognition of high-risk and nonspecific implantations. Analysis of the available literature indicates that therapeutic decisions must be individualized and guided by the implantation site and assessment of hemorrhagic risk, rather than gestational age or absolute β-hCG values. Understanding these principles represents the basis for reducing serious complications and for the development of future diagnostic and therapeutic algorithms, thereby improving treatment outcomes.