Management of the twin-to-twin transfusion syndrome (TTTS)

Abstract

Twin-to-twin transfusion syndrome (TTTS) is a severe complication of multiple pregnancy occurring in 10–12% of monochorionic twins. This complication is mainly due to the presence of unbalanced arterio-venous anastomoses between placental branches of the umbilical circulations. The natural history of TTTS is variable. It is often difficult to predict whether a patient will show stable rather than rapidly progressive disease. A formal staging system has been suggested based on the sonographic time sequence of cases with progressive deterioration and poorer outcome. The mortality of untreated TTTS has been quoted to be more than 80% with advances in neonatal care the mortality rate may have decreased. The three most commonly used therapies for mid-trimester TTTS are amnioreduction, fetoscopic laser coagulation of the vascular anastomoses and septostomy. Outcome for fetuses with TTTS treated with amnioreduction depends on several antenatal variables which may help in counseling patients. Fetoscopic laser coagulation of vascular anastomoses represents an important evolution in the surgical treatment of TTTS. The management of the TTTS according to stage should be corroborated with an appropriate clinical trial.