What is Twin-Twin Transfusion Syndrome?

Twin-twin transfusion syndrome (TTTS) is a rare, serious condition that can occur in pregnancies when identical twins share a placenta. Abnormal blood vessel connections form in the placenta and allow blood to flow unevenly between the babies. One twin − called the donor – becomes dehydrated; and the other − called the recipient − develops high blood pressure and produces too much urine and over fills the amniotic sac.