Addressing Patient-Provider Communication Gaps in Vanishing Twin Syndrome: Implications for Patient Care and Clinical Guidelines.

: Vanishing twin syndrome (VTS) represents a complex and under-recognized phenomenon in multifetal pregnancies, associated with both clinical uncertainty and significant psychosocial impact. Despite its frequency, gaps remain in diagnostic clarity, international guidelines, and communication strategies with patients and families. : This hybrid review integrates narrative and systematic elements to assess the diagnostic, clinical, and psychosocial gaps in VTS. A systematic literature search was conducted across Medline/PubMed, CINAHL, PsycINFO, EBM Reviews, and Scopus using terms such as "vanishing twin syndrome," "patient-provider communicat*," and "bereave* care." Sources included systematic reviews, randomized controlled trials, cohort studies, and qualitative studies. Exclusion criteria were outdated publications (>10 years old). : Evidence revealed multiple domains of concern. Clinical risks and diagnostics remain poorly defined, with inconsistent recognition of maternal and neonatal complications. Psychosocial impacts were prominent, encompassing grief, identity disruption, and unmet support needs. Patient-provider communication was frequently inadequate, with insufficient training and lack of standardized language. International guidelines varied widely in scope, with only a few of them providing clear recommendations for bereavement care in multifetal loss contexts. : Emerging discourse highlights the limitations of the traditional fission model and alternative conceptual frameworks, such as Herranz's model, for understanding VTS. These theoretical differences underscore the need for precise terminology and consistent diagnostic practices. Clinical implications extend to prenatal screening, obstetric management, and the integration of psychosocial support. Patient-centered communication and structured support initiatives (e.g., the Butterfly Project) demonstrate the potential to bridge communication gaps and improve care experiences. : VTS requires recognition as both a medical and psychosocial condition. Improved clinical definitions, harmonized international guidelines, and emphasis on empathetic communication are essential to address the current gaps. Integrating these elements into practice may enhance patient outcomes and provide families with validation and support following multifetal loss.