Prediction of outcome of twin twin transfusion syndrome at presentation

Abstract

Aim: The aim of this study was to determine what factors are important in prediction of outcome in twin twin transfusion syndrome (TTTS) at presentation.Methods: A retrospective review was performed of all cases of TTTS managed at the Mater Mother's Hospital, Brisbane, Australia from 1994 until 2001. TTTS was diagnosed when there was coexisting oligohydramnios (MVP < 2 cm) and polyhydramnios (MVP > 8 cm) in a monochorionic pregnancy.Results: There were 50 cases of TTTS during this time (100 fetuses). Overall, there was a 61% survival rate, with 14% of the fetuses having an NND, 23% were stillborn and there was one termination of pregnancy. Both babies survived in 55% of pregnancies, one survived in 16% and both twins were lost in 29%. The average gestation at diagnosis was 21.5 weeks (range 16–29) and the average gestation at delivery was 28.5 weeks (range 16–36). Sixty percent of pregnancies had a mean of 2.1 amnioreduction performed, and 2002 ± 976 mL was removed. The poorest prognostic factor was the presence of hydrops in the recipient twin. Hydrops at presentation resulted in only a 36% survival for either twin in the affected pregnancy. Hydrops resolved spontaneously in two out of 11 cases and these were the only hydropic twins to survive. At the time of presentation, abnormal Dopplers in the recipient twin were associated with significantly poorer survival than for normal Dopplers (27% vs. 64% P = 0.02) but in contrast to other studies there was no significant difference seen in outcomes for the presence of abnormal Dopplers in the donor twin. Other individual factors did not prove to be good at predicting outcome.Conclusions: The poorest prognostic indicators for survival in TTTS were the presence of hydrops and abnormal umbilical artery and venous Dopplers in the recipient. Research into identifying good prognostic markers may identify subgroups of TTTS that may benefit from more aggressive therapies in order that we might further improve outcomes.