title: Antenatal factors at diagnosis that predict outcome in twin-twin transfusion syndrome.
abstract: OBJECTIVE
  We sought to identify clinical factors at diagnosis that predict outcome in twin-twin transfusion syndrome.
  
  
  METHODS
  In this retrospective series 23 patients with twin-twin transfusion syndrome were seen in a tertiary referral fetal medicine center over a 3-year period. Ten antenatal factors were assessed to determine their ability to predict outcome by use of ordered logistic regression. These factors were the following: (1) absent or reversed end-diastolic flow in the umbilical artery, nonvisible bladder, anhydramnios, and estimated fetal weight of <3rd percentile in the donor; (2) pulsatile umbilical vein, either absent or reversed end-diastolic flow in the ductus venosus, or both, and tricuspid-mitral valve regurgitation in the recipient; and (3) gestational age at 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), selective feticide (n = 5; 4 also had amnioreduction), septostomy (n = 4; 1 also had amnioreduction), and delivery (n = 2). Two patients miscarried before treatment.
  
  
  RESULTS
  The chance of survival of both twins fell and double deaths increased linearly with increasing number of adverse factors (P =.026). A low chance of survival was independently associated with absent or reversed end-diastolic flow in the donor umbilical artery (P =.02) and with a pulsatile umbilical vein or absent or reversed end-diastolic flow in the ductus venosus (P =.03) of the recipient. The probability of at least one twin surviving was only 33% if there was absent or reversed end-diastolic flow in the donor umbilical artery or 37% when abnormal venous recordings were seen in the recipient. An arterioarterial anastomosis detected at diagnosis also influenced prognosis, with all twins surviving when an arterioarterial anastomosis was identified (P =.04).
  
  
  CONCLUSIONS
  Three factors identified at diagnosis independently predict poor survival in twin-twin transfusion syndrome-absent or reversed end-diastolic flow in the donor umbilical artery, abnormal pulsatility of the venous system in the recipient, and absence of an arterioarterial anastomosis. These may have a role in the counseling of parents and in selecting the appropriate treatment strategy.
authors.affiliation: Centre for Fetal Care, Imperial College School of Medicine, London, United Kingdom.
authors.forename: M J
authors.initials: MJ
authors.lastname: Taylor
authors.forename: M L
authors.initials: ML
authors.lastname: Denbow
authors.forename: K R
authors.initials: KR
authors.lastname: Duncan
authors.forename: T G
authors.initials: TG
authors.lastname: Overton
authors.forename: N M
authors.initials: NM
authors.lastname: Fisk
mesh_terms: D001158:Arteries / Q000002:abnormalities / Q000196:embryology; D003971:Diastole; D005260:Female; D005330:Fetofetal Transfusion / Q000150:complications / Q000401:mortality / Q000503:physiopathology*; D006801:Humans; D011247:Pregnancy; D011296:Prenatal Diagnosis; D011379:Prognosis; D011673:Pulsatile Flow; D012039:Regional Blood Flow; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome; D014469:Umbilical Arteries / Q000503:physiopathology; D014680:Veins / Q000196:embryology