Antenatal factors at diagnosis that predict outcome in twin-twin transfusion syndrome

OBJECTIVE: We sought to identify clinical factors at diagnosis that predict outcome in twin-twin transfusion syndrome. STUDY DESIGN: In this retrospective series 23 patients with twin-twin trans fusion syndrome were seen in a tertiary referral fetal medicine center over a 3-year period. Ten antenatal factors were assessed to determine their ab ility to predict outcome by use of ordered logistic regression. These facto rs were the following: (1) absent or reversed end-diastolic flow in the umb ilical artery, nonvisible bladder, anhydramnios, and estimated fetal weight of <3rd percentile in the donor; (2) pulsatile umbilical vein, either abse nt or reversed end-diastolic flow in the ductus venosus, or both, and tricu spid-mitral valve regurgitation in the recipient; and (3) gestational age a t presentation, estimated fetal weight discordancy. absent arterioarterial anastomosis, and spontaneous rupture of the membranes or cervical change as pregnancy factors. Management comprised serial amnioreduction (n = 10), se lective feticide (n = 5; 4 also had amnioreduction), septostomy (n = 4; 1 a lso had amnioreduction), and delivery (n = 2). Two patients miscarried befo re treatment. RESULTS: The chance of survival of both twins fell and double deaths increa sed linearly with increasing number of adverse factors (P = .026). A low ch ance of survival was independently associated with absent or reversed end-d iastolic flow in the donor umbilical artery (P = .02) and with a pulsatile umbilical vein or absent or reversed end-diastolic flow in the ductus venos us (P =.03) of the recipient. The probability of at least one twin survivin g was only 33% ii there was absent or reversed end-diastolic flow in the do nor umbilical artery or 37% when abnormal venous recordings were seen in th e recipient. An arterioarterial anastomosis detected at diagnosis also infl uenced prognosis. with all twins surviving when an arterioarterial anastomo sis was identified (P = .04), CONCLUSIONS: Three factors identified at diagnosis independently predict po or survival in twin-twin transfusion syndrome-absent or reversed end-diasto lic flow in the donor umbilical artery, abnormal pulsatility of the venous system in the recipient, and absence of an arterioarterial anastomosis. The se may have a role in the counseling of parents and in selecting the approp riate treatment strategy.