Abstract

Acardiac twin or Twin Reversed Arterial Perfusion sequence (TRAPS) is a unique and extreme complication seen in monochorionicmultifetal pregnancies. It comprises an often normal twin pumping deoxygenated arterial blood in retrograde through an acardiac, dysmorphic counterpart. Recently, a 2.6% incidence among monochorionic twins has been cited. For the pump/donor twin, mortality often exceeds 50% commonly from heart failure and prematurity. Acardiac twinning with a surviving donor twin has yet to be described in our setting. We describe a 28-year-old para 0+1 presenting in the second trimester with a twin pregnancy complicated by polyhydramnios of the donor viable twin and a non-viable recipient twin inadvertently diagnosed as a single fetal demise of a grossly malformed twin. The case was expectantly managed resulting in spontaneous preterm delivery and survival of the donor twin. TRAPS necessitates a high index of suspicion and a thorough sonographic evaluation in monochorionicmultifetal pregnancies.