title: Risk of persistent pulmonary hypertension of the neonate in twin-to-twin transfusion syndrome.
abstract: BACKGROUND
  Chronic twin-to-twin transfusion syndrome (TTTS) is a complication of monochorionic twin gestations and is associated with high perinatal mortality and increased neurological, cardiovascular and renal morbidity.
  
  
  OBJECTIVE
  To report the risk of severe persistent pulmonary hypertension of the newborn (PPHN) in TTTS and discuss the possible association between severe PPHN and TTTS.
  
  
  METHODS
  All cases of monochorionic twins with severe PPHN at birth admitted to our nursery between June 2002 and July 2006 were reviewed retrospectively. We compared the incidence of severe PPHN in monochorionic twins with and without TTTS. Severe PPHN was diagnosed according to clinical and ultrasound criteria when an infant with a structurally normal heart had (1) severe hypoxemia and (2) evidence of a right-to-left shunt on persistent ductus arteriosus or foramen ovale, requiring treatment with inhaled nitric oxide (iNO).
  
  
  RESULTS
  In a consecutive series of 73 twin pregnancies with TTTS, 4 of the 135 live-born twins (3%) were affected by severe PPHN. All reacted promptly to treatment with iNO. The incidence of severe PPHN in monochorionic twins without TTTS was 0% (0/161).
  
  
  CONCLUSIONS
  In view of the severe clinical course in PPHN and need for adequate and prompt treatment with iNO, perinatologists should be aware of the increased risk of severe PPHN in TTTS.
authors: Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands.
authors: Bas
authors: B
authors: Delsing
authors: Enrico
authors: E
authors: Lopriore
authors: Nico
authors: N
authors: Blom
authors: Arjan B
authors: AB
authors: Te Pas
authors: Frank P
authors: FP
authors: Vandenbussche
authors: Frans J
authors: FJ
authors: Walther
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D001993:Bronchodilator Agents / Q000627:therapeutic use*; D015897:Comorbidity; D004452:Echocardiography; D017809:Fatal Outcome; D005260:Female; D005330:Fetofetal Transfusion / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery; D005332:Fetoscopy; D005865:Gestational Age; D006801:Humans; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000453:epidemiology* / Q000209:etiology; D007231:Infant, Newborn; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D009569:Nitric Oxide / Q000627:therapeutic use*; D011247:Pregnancy; D012307:Risk Factors; D014430:Twins, Monozygotic
chemical_list: D001993:Bronchodilator Agents; D009569:Nitric Oxide