Iincidence

Iincidence of Twin–Twin Transfusion Syndrome

Twin-to-twin transfusion is a complication unique to monochorionic twin pregnancies. Although previously known by such terms as feto–fetal transfusion syndrome, autotransfusion syndrome, intrauterine parabiotic syndrome,17 twin–twin transfusion syndrome (TTTS) is now commonly used. 

The incidence of TTTS ranges between 1.7% and 6.9% of twin pregnancies and between 5% and 15% of monochorionic twins,18–21 although the incidence may be higher and may be influenced by criteria used to establish the diagnosis of TTTS.18,22,23 The purpose of this chapter is to evaluate the reported incidence rates as well as assessing predictors for the development of TTTS and prognostic factors for adverse outcomes.