title: Fetoscopic laser coagulation for severe twin-to-twin transfusion syndrome: factors influencing perinatal outcome, learning curve of the procedure and lessons for new centres.
abstract: OBJECTIVE
  To evaluate the effects of operator experience on perinatal outcome in a single centre.
  
  
  METHODS
  Prospective consecutive cohort study.
  
  
  METHODS
  Regional tertiary referral Fetal Medicine Centre in the UK.
  
  
  METHODS
  Pregnant women with monochorionic twin pregnancies complicated by severe twin-to-twin transfusion syndrome (TTTS) (at ≤26 completed weeks of gestatiuon) treated by fetoscopic laser coagulation (FLC) between October 2004 and November 2009.
  
  
  METHODS
  Pregnancy characteristics and outcomes were collected. Logistic regression analysis was employed to determine the effect of a priori defined variables on outcome.
  
  
  METHODS
  Perinatal survival (survival to 28 days or beyond) for one or more twins.
  
  
  RESULTS
  There were 164 consecutive sets of monochorionic twins. The median gestational age (GA) at FLC was 20.4 weeks (interquartile range 18-22.1 weeks), the median interval from FLC to delivery was 88.5 days (interquartile range 53-101 days) and the median GA at delivery was 33.2 weeks (interquartile range 29.7-34.9 weeks). The overall survival was 62%; perinatal survival of one or more twins was 85%. These outcomes improved after about 61 procedures were performed, and after about 3.4 years of experience. Univariate logistic regression analysis indicated that Quintero stage-IV disease decreased (OR 0.26; 95% CI 0.10-0.69) and prolongation of GA at delivery increased the survival of the twins (OR 1.34; 95% CI 1.12-1.60) (P < 0.01). Increasing experience of the procedure by operator led to a significant increase in perinatal survival (P < 0.01; OR 4.59; 95% CI 1.84-11.44). Multivariate logistic regression analysis indicated that only GA at delivery increased survival overall (OR 1.34; 95% CI 1.12-1.60; P = 0.01).
  
  
  CONCLUSIONS
  These data indicate that both relatively large numbers treated and experience with FLC minimises any adverse outcome in monochorionic pregnancies with severe TTTS.
authors.affiliation: School of Clinical and Experimental Medicine, University of Birmingham, Edgbaston, Birmingham, UK.
authors.forename: R K
authors.initials: RK
authors.lastname: Morris
authors.forename: T J
authors.initials: TJ
authors.lastname: Selman
authors.forename: A
authors.initials: A
authors.lastname: Harbidge
authors.forename: W I
authors.initials: WI
authors.lastname: Martin
authors.forename: M D
authors.initials: MD
authors.lastname: Kilby
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000209:etiology; D005330:Fetofetal Transfusion / Q000401:mortality / Q000601:surgery*; D005332:Fetoscopy / Q000379:methods*; D006801:Humans; D017075:Laser Coagulation / Q000379:methods*; D059032:Learning Curve; D054238:Perinatal Mortality; D011183:Postoperative Complications / Q000209:etiology; D011247:Pregnancy; D011256:Pregnancy Outcome; D011295:Prenatal Care / Q000379:methods*; D011446:Prospective Studies; D014430:Twins, Monozygotic; D055815:Young Adult