Twin reversed arterial perfusion

The other limbs may be partially present or missing, and internal structures of the torso are often poorly formed.

[2] Due to related problems including the rapid growth of the acardiac twin, polyhydramnios, umbilical cord entanglement and congestive heart failure due to high output, there is a high mortality rate for the pump twin if left untreated.

[7] Doppler interrogation will confirm that blood flow in the acardiac twin is in the reverse direction, entering via the umbilical cord artery and exiting through the vein.

[8] After diagnosis, ultrasound and amniocentesis are used to rule out genetic abnormalities in the pump twin.

[3] Or a radiofrequency ablation needle may be used to coagulate the blood in the acardiac twin's umbilical cord.

Vaginal birth is possible unless the fetus is in distress, although it is recommended that the delivery take place at a hospital with NICU capabilities.

Illustration of TRAPS pregnancy. On the left, the acardiac twin. The pump twin is on the right. Selective termination of the acardiac twin can reduce the risk of death of the pump twin.
An Acardiac twin