title: Intervention versus a conservative approach in the management of TRAP sequence: a systematic review.
abstract: OBJECTIVE
  In the management of twin reversed arterial perfusion (TRAP) sequence, we wished to (i) determine if intervention is better than a conservative approach and (ii) assess if any of the apparent adverse prognostic indicators could guide intervention.
  
  
  METHODS
  A systematic review was conducted between 1994 and 2014. Data extracted were inspected for heterogeneity. Overall rates and confidence intervals (CIs) for each prognostic factor were calculated. Where there were comparative data, the odds ratio (OR) was calculated.
  
  
  RESULTS
  Twenty-six studies were included in the review. When all cases were considered, intervention either by cord occlusion or by ablation conferred a better survival rate compared with conservative management (OR=2.22, 95% CI 1.23-4.01, heterogeneity I2=37%, P=0.008). This difference was greater in the presence of one or more poor prognostic features (OR=8.58, 95% CI 1.47-49.96, heterogeneity I2=0%, P=0.02). Survival was better using ablative techniques compared to cord occlusion (OR=9.84, 95% CI 1.56-62.00, heterogeneity I2=0%, P=0.01).
  
  
  CONCLUSIONS
  Intervention either by cord occlusion or by ablation confers a better survival rate compared to conservative management. This appears more compelling if there are one or more poor prognostic features. Ablative techniques are superior to cord occlusion. There were insufficient data to determine which poor prognostic features should guide management.
authors.forename: Fionnuala
authors.initials: F
authors.lastname: Mone
authors.forename: Priscilla
authors.initials: P
authors.lastname: Devaseelan
authors.forename: Stephen
authors.initials: S
authors.lastname: Ong
mesh_terms: D055011:Ablation Techniques; D004200:Diseases in Twins / Q000401:mortality / Q000628:therapy*; D004621:Embolization, Therapeutic; D005318:Fetal Heart / Q000002:abnormalities*; D046128:Fetal Therapies / Q000379:methods*; D006330:Heart Defects, Congenital / Q000401:mortality / Q000628:therapy*; D006801:Humans; D011379:Prognosis; D014430:Twins, Monozygotic