Twin Reversed – Arterial Perfusion Sequence: The Experience of a Tertiary Referral Hospital in the Philippines with Acardiac Twinning

  • Joyceline Noemi I. Silao
Keywords: acardiac twins, pump twin, Twin Reverse Arterial Perfusion Sequence (TRAP) sequence, Chorangiopagus parasiticus (CAPP)


Twin reversed-arterial perfusion sequence is a rare complication of
monochorionic pregnancies. It is characterized by the hemodynamic
dependence of the recipient twin on a pump twin. The recipient twin
exhibits lethal malformations. The pump twin’s survival is threatened
by congestive heart failure and prematurity. Mortality rate ranges
from 50% to 75% if untreated. Mortality is reduced to 13.6% with
surgical intervention.1
Five cases of twin reversed-arterial perfusion
sequence were seen in the Philippine General Hospital, a university
hospital and tertiary referral center. All cases had acardiac twins and
were managed conservatively. The first three cases were previously
reported. Two additional cases were encountered in 2007-2008 and
are here presented. The first case was in a 41 year old G8P7 (7007) with
diffuse toxic goiter and hypertension. The pregnancy was plagued
with polyhydramnios and cardiac decompensation of the pump twin
resulting in fetal death- in-utero. The second case was in a 37 year old
G3P2 (2002) who had no medical co-morbidities. There were no risk
factors and the outcome was a term livebirth