title: Risk factors associated with preterm delivery after fetoscopic laser ablation for twin-twin transfusion syndrome.
abstract: OBJECTIVE
  Despite improved perinatal survival following fetoscopic laser ablation (FLA) for twin-twin transfusion syndrome (TTTS), prematurity remains an important contributor to perinatal mortality and morbidity. The objective of the study was to identify risk factors for complicated preterm delivery after FLA.
  
  
  METHODS
  Retrospective cohort study of prospectively collected data on maternal/fetal demographics and pre-operative, operative and postoperative variables of 459 patients treated with FLA in three USA fetal centers. Multivariate linear regression was performed to identify significant risk factors associated with preterm delivery, which were cross-validated using the k-fold method. Multivariate logistic regression was performed to identify risk factors for early compared with late preterm delivery based on median gestational age at delivery of 32 weeks.
  
  
  RESULTS
  There were significant differences in case selection and outcomes between the centers. After controlling for the center of surgery, multivariate analysis indicated that a lower maternal age at procedure, a history of previous prematurity, shortened cervical length, use of amnioinfusion, a cannula diameter of 12 French (Fr), lack of a collagen plug placement and iatrogenic preterm premature rupture of membranes (iPPROM) were significantly associated with a lower gestational age at delivery.
  
  
  CONCLUSIONS
  Specific fetal/maternal and operative variables are associated with preterm delivery after FLA for the treatment of TTTS. Further studies to modify some of these variables may decrease the perinatal morbidity after laser therapy.
authors.affiliation: Section of Maternal-Fetal Medicine, Obstetrics, Gynecology and Reproductive Sciences, Yale School of Medicine, New Haven, CT, USA; Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX, USA.
authors.forename: R
authors.initials: R
authors.lastname: Papanna
authors.forename: D
authors.initials: D
authors.lastname: Block-Abraham
authors.forename: L K
authors.initials: LK
authors.lastname: Mann
authors.forename: I A
authors.initials: IA
authors.lastname: Buhimschi
authors.forename: M
authors.initials: M
authors.lastname: Bebbington
authors.forename: E
authors.initials: E
authors.lastname: Garcia
authors.forename: N
authors.initials: N
authors.lastname: Kahlek
authors.forename: C
authors.initials: C
authors.lastname: Harman
authors.forename: A
authors.initials: A
authors.lastname: Johnson
authors.forename: A
authors.initials: A
authors.lastname: Baschat
authors.forename: K J
authors.initials: KJ
authors.lastname: Moise
mesh_terms: D000328:Adult; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000000981:diagnostic imaging / Q000209:etiology* / Q000601:surgery*; D005330:Fetofetal Transfusion / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D005332:Fetoscopy / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D007231:Infant, Newborn; D053685:Laser Therapy; D016015:Logistic Models; D011237:Predictive Value of Tests; D011247:Pregnancy; D047928:Premature Birth; D012189:Retrospective Studies; D012307:Risk Factors; D014463:Ultrasonography
keywords: fetoscopy; laser photocoagulation; predictors; preterm delivery; twin-twin transfusion syndrome