Twin-Twin Transfusion Syndrome (TTTS) | Symptoms & Causes

What causes TTTS?

The exact cause of TTTS is unknown. There are several variations of blood vessel development that may lead to unbalanced blood exchange. In addition, the fetus's response to altered blood volume may worsen the condition.

What are the symptoms of TTTS?

Symptoms of the recipient twin:

  • very large amount of urine in the bladder
  • too much amniotic fluid in the sac (polyhydramnios)
  • larger than the donor twin and possibly swollen with too much blood
  • congenital heart failure from an excess of blood

Symptoms of the donor twin:

  • little or no urine in the bladder
  • too little amniotic fluid in the sac (oligohydramnios)
  • much smaller than the recipient twin