title: Risk factors for persistence of pulmonary arterial branch stenosis in neonates and young infants.
abstract: BACKGROUND
  Pulmonary arterial branch stenosis (PBS) in neonates is considered to be transient. However, PBS has been found not only in neonates, but also in young infants. Among these patients, we encountered several patients whose PBS was still present after the age of 1 year.
  
  
  METHODS
  To clarify the natural history of PBS in neonates and young infants, we retrospectively reviewed the records of 103 patients diagnosed with PBS in the neonatal period and early infancy.
  
  
  RESULTS
  The PBS findings were improved in all patients. Pulmonary arterial branch stenosis disappeared in 94 patients by the age of 1 year (group A), but persisted after I year of age in nine patients (group B). Group B patients had a significantly lower mean birth weight and greater deltavelocity (the difference in the peak flow velocity between the main pulmonary artery and stenotic branch) at diagnosis than group A patients. Incidences of low birth weight (< 2,500 g) and deltavelocity above 1.2 m/s were significantly higher in group B than group A patients. There was no significant difference in the frequency of premature infants (gestational age < 36 weeks) between the groups, suggesting that intrauterine growth retardation may be related to developmental abnormalities of the pulmonary arterial branch.
  
  
  CONCLUSIONS
  All cases of PBS in neonates and young infants were improved. However, PBS persisted in some patients after the age of 1 year. Low birth weight and deltavelocity above 1.2 m/s are risk factors for persistent PBS. Pulmonary arterial branch stenosis was not present after the age of 1 year in 62 of 63 patients without either of these risk factors.
authors.affiliation: Department of Pediatrics, Faculty of Medicine, Kagoshima University, Japan. uichi@m2.kufm.kagoshima-u.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Nomura
authors.forename: M
authors.initials: M
authors.lastname: Nakamura
authors.forename: Y
authors.initials: Y
authors.lastname: Kono
authors.forename: T
authors.initials: T
authors.lastname: Fukushige
authors.forename: A
authors.initials: A
authors.lastname: Shimago
authors.forename: J
authors.initials: J
authors.lastname: Kamimura
authors.forename: J I
authors.initials: JI
authors.lastname: Nishi
authors.forename: M
authors.initials: M
authors.lastname: Yoshinaga
authors.forename: K
authors.initials: K
authors.lastname: Miyata
mesh_terms: D000367:Age Factors; D001783:Blood Flow Velocity; D018450:Disease Progression; D004452:Echocardiography; D006801:Humans; D007223:Infant; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D011651:Pulmonary Artery / Q000002:abnormalities*; D011666:Pulmonary Valve Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012189:Retrospective Studies; D012307:Risk Factors