Twin Reversed Arterial Perfusion Syndrome (TRAP or Acardiac Twin)-A Case Report

Abstract

Twin reversed arterial perfusion (TRAP) syndrome is a rare condition (0.3:10,000 births) that occurs in monochorionic twin pregnancies, resulting in coexistence of a normal "pump" twin and an acardiac twin. The acardiac twin is dependent upon the normal twin to provide circulation by means of vascular anastomosis. Many of the bizarre defects are felt to be caused by low oxygen tension and this causes dramatic alteration in the twin fetal physiology and high prenatal mortality. The acardiac twin is a parasite, putting the pump fetus at risk of high output cardiac failure. Overall only 50% of pump twins survive. We present a case in a twenty year female, gravida two, para one, living one, full term normal pregnancy, ultrasound showed twin pregnancy. Following delivery, the first fetus survived only for one day and the second fetus showed features of TRAP syndrome.

Keywords: Acardiac twin; fetal anomaly; twin reversed arterial perfusion syndrome.

[Table/Fig-1]:

Gross photograph of fetus showing cystic dilated sac around head, neck & upper half of the body with deformed face and upper limb.

[Table/Fig-2]:

Gross photograph showing loculated cystic spaces around upper half of the body with thorax & abdominal contents having rudimentary heart, absence of lung, liver & spleen.

[Table/Fig-3]:

Microphotograph of rudimentary heart showing cystic spaces with myocardium. (H&E x 100)

[Table/Fig-4]:

Microphotograph of umbilical card showing two veins, one artery and one rudimentary artery. (H&E x 100)

[Table/Fig-5]:

Gross photograph showing cranial cavity having only membranous vascular structure.