Research Progress on Twin Reversed Arterial Perfusion Sequence Characteristics: A Narrative Review

Objective: Twin Reversed Arterial Perfusion (TRAP) sequence is a rare and severe complication unique to monochorionic multiple gestations. This article systematically reviews recent research findings and incorporates previous cutting‑edge studies to comprehensively analyze new developments in the diagnosis and management of TRAP, so as to provide valuable insights for optimizing clinical practice. Mechanism: The hallmark of TRAP sequence is that a normally functioning pump twin supplies blood to its acardiac parasitic twin through arterial‑arterial anastomosis on the placental surface. Cardiac dysfunction in TRAP predominantly arises from high‑output heart failure, and the acardiac twin frequently presents multi‑organ developmental anomalies. Without timely intervention, persistent high‑output circulatory overload significantly raises the risk of severe heart failure and even death in the pump twin. Findings in Brief: Advances in fetal medicine, imaging techniques, and interventional therapies have achieved substantial progress in deciphering etiological mechanisms of TRAP, enabling precise diagnosis and promoting individualized treatment strategies for this condition. Conclusions: Updated understanding on diagnosis and management of TRAP sequence provides important references for clinical decision‑making in this rare monochorionic twin complication.