Twin Reversed Arterial Perfusion (TRAP) | Diagnosis & Treatments
How is TRAP diagnosed?
Your doctor can diagnose TRAP based on a prenatal ultrasound.
Signs of TRAP include:
- The pump twin is larger than the acardiac twin.
- Polyhydramnios (excessive accumulation of amniotic fluid) developed by the pump twin and possibly heart failure, which can be seen on ultrasound.
If your doctor sees these signs of TRAP, you may also receive a fetal echocardiography, which looks directly at the heart of the pump twin to assess how it’s functioning.
How is TRAP treated?
Treatment options for TRAP may include:
- Monitoring: Close monitoring of the pregnancy through ultrasound and other diagnostic techniques to assess the health and development of both twins.
- Intervention: In severe cases, Boston Children’s most common approach to treating TRAP is to separate the circulation between the twins.This involves either obliterating blood supply to the acardiac twin by radiofrequency ablation or coagulating and ligating its umbilical cord. The specific approach will be considered by our fetal surgeons according to the findings documented by prenatal ultrasound. The procedure is performed during the second trimester through a single puncture in the mother's abdomen.
This will increase the chance of survival in the pump twin by decreasing the potential for heart failure. There is an increased chance of preterm labor after this procedure, so you will be monitored closely through the rest of your pregnancy. - Delivery: In severe cases of TRAP, or if the pump twin’s health is at extreme risk, we may recommend earlier delivery of the twins to save the life of the pump twin.
Your prenatal ultrasound findings will determine the specific approach doctors take for your pregnancy.
