Testing & diagnosis for Twin Reversed Arterial Perfusion (TRAP) in children

How is TRAP Diagnosed?

Your doctor will be able to make a diagnosis based on the mother’s prenatal ultrasound.

  • Often the pump twin's size will be larger than the acardiac twin.
  • Also the pump twin may develop polyhydramnios (excessive accumulation of amniotic fluid) and possibly heart failure, which can be seen on ultrasound.

If your doctor sees these signs, you may also get a fetal echocardiography, which looks directly at the heart of the pump twin.