What is TTTS?

TTTS stands for Twin-to-Twin Transfusion Syndrome. It is a condition that affects some identical twins in the womb. When the twins share a placenta (as is very often the case with identical twins), sometimes they will do so unequally: one twin will receive too much of the blood/nourishment from the placenta, while the other receives too little. In fact, blood from one twin (the "donor twin") is actually diverted into the other twin (the "recipient twin"). 

This condition is very dangerous to both babies. Many do die and, those who do survive, sometimes have lasting medical conditions.... There is hope, though! Many do survive and go on to be perfectly happy and healthy babies. But awareness is key! Why is it so dangerous? It must be noted that TTTS is a disease of the placenta, not the babies. Babies affected by TTTS are completely normal. It's simply a matter of making it through the pregnancy.
However, due to the babies not receiving an appropriate amount of blood from the placenta, they are both in danger: the "donor twin" can suffer from anemia or simply fail to develop. And, the "recipient twin" can suffer from heart failure. TTTS affects approximately 1 in every 1000 pregnancies. Despite that, though, it is not a widely known or understood condition.

Related Links:
Fetal Hope Foundation

TTTS Foundation

Twin-to-twin transfusion syndrome (Wikipedia)

Twin to Twin Transfusion Syndrome (TTTS) (University of Maryland Medical Center)

Twin to Twin TransfusionSyndrome (TTTS)(American Pregnancy Association)

Twin to Twin Transfusion Syndrome (UCSF Children's Hospital)

Twin-Twin Transfusion Syndrome (TTTS) (Texas Children's Hospital)