TRAP Sequence in an Acardiac Twin
Athita Chanthasenanont MD*, Densak Pongrojpaw MD*
Affiliation : * Department of Obstetrics and Gynecology, Faculty of Medicine, Thammasat University, Pathumthani
Case Report : The authors present a case of an acardiac twin gestation diagnosed sonographically at 20
weeks with evidence of twin reversed-arterial perfusion (TRAP) sequence. The acardius appeared to be less
than half the estimated weight of the pump twin. The acardius was identified as an amorphous mass, without
extremities. The parents chose expectant management rather than surgical intervention. Observation by
serial sonographic and color Doppler evaluation was performed. At 34 weeks, a healthy infant was delivered
by cesarean section after showing signs of fetal congestive heart failure (CHF). The acardius was 2/3 the size
of the infant at delivery.
Conclusion : Expectant management with close antepartum surveillance deserves consideration in cases of
monozygotic twins with TRAP sequence. Neonatal mortality of the pump twin diagnosed antenatally may be
considerably less than reported.
Keywords : Acardiac twin, TRAP sequence, Fetal heart failure
