Twin-Twin Transfusion Syndrome (TTTS)

What is TTTS?

Twin-twin transfusion syndrome (TTTS) is a problem where one fetus — the donor twin — pumps blood to the other fetus — the recipient twin. The condition occurs in about 10 percent of all pregnancies where identical twins share a placenta. That amounts to about 2,000 patients per year in the U.S.

Without intervention, the recipient twin receives too much blood and may develop fluid overload, heart failure and die, and the donor twin may die from not having enough blood (severe anemia).

Almost all identical twins exchange blood across the placenta, although usually the exchange is balanced. In TTTS, the blood connections in the placenta are abnormal and the blood passes unequally between the two fetuses. TTTS occurs in varying stages of severity, which may or may not progress to the point where intervention is needed.

How we care for TTTS

Through the joint work of researchers, genetic specialists, surgeons and other care providers, the Boston Children's Hospital Advanced Fetal Care Center is breaking new ground in understanding and successfully treating a wide variety of fetal health concerns, including TTTS.