Twin reversed arterial perfusion (TRAP) sequence – a case report and review of literature

Abstract

Twin reversed arterial perfusion (TRAP) sequence (acardiac twin) is a rare complication of monochorionic pregnancy characterized by single arterial to arterial vascular anastomosis between twins. In this unique haemodynamic arrangement, the structurally normal pump twin will perfuse its abnormal co-twin (acardiac) in a retrograde manner through these anastomoses, with potential for cardiac overload and heart failure in the pump twin and high fetal mortality. Definitive fetal intervention has been recommended in the literature for high (>50%) twin weight ratio (TWR). We present a case of twin reversed arterial perfusion managed expectantly as no signs of cardiac decompensation were encountered in the pump twin.