Ultrasound Doppler findings of a Twin Reversed Arterial Perfusion Sequence (TRAP)

Abstract

Twin reversed arterial perfusion (TRAP) sequence is a rare pregnancy complication occurs in an identical twin pregnancy that share a single placenta. TRAP sequence is a twin's pregnancy includes a normal-developed viable pump fetus and an abnormal usually nonviable acardiac fetus. The nonviable acardiac fetus depends on the pump fetus for his blood supply and put the pump fetus at risk of high cardiac output heart failure and congenital anomalies with high mortality rate. Gray-scale ultrasound and color and pulsed Doppler imaging is a noninvasive accessible imaging modality for the diagnosis of TRAP sequence. Early diagnosis of such conditions is mandatory in order to apply the proper therapeutic measures and to help the normal developed pump fetus to survive. The main goal of management is to interrupt blood supply to the nonviable acardiac fetus to reduce the strain on the heart of the pump fetus thus, increase the chance of survival.

Keywords: Monoamniotic twin (share an amniotic sac). Acardiac fetus; Monochorionic twin (share a single placenta); Pump fetus; Twin reversed arterial perfusion sequence.