Twin-to-twin transfusion syndrome (TTTS) is a rare condition that occurs only in identical twins when they are in the womb. The cause is unknown. It occurs when blood moves from one twin to the other. The twin that loses the blood is called the donor twin, and the twin that receives the blood is called the recipient twin.
After birth, both babies may have health problems, depending upon how severe the transfusion was. The donor twin is usually born smaller than the other twin, and is usually pale, dehydrated and anemic. The donor twin may have too little blood and may need a blood transfusion. The recipient twin is usually born larger and may need to have the amount of blood in his/her body reduced. Because of the extra blood, the recipient twin will be red, and will have increased blood pressure. The recipient twin may develop heart problems and may need medications to strengthen the heart.
This condition is usually diagnosed during pregnancy by ultrasound. Treatment before birth may be done. One method type of treatment is frequent amniocentesis around the recipient twin to drain the excess amount of amniotic fluid. Another method of treatment is fetal laser surgery to interrupt the flow of blood from one twin to the other.