title: Size at birth by gestational age and hospital mortality in very preterm infants: results of the area-based ACTION project.
abstract: BACKGROUND
  Size at birth is an important predictor of neonatal outcomes, but there are inconsistencies on the definitions and optimal cut-offs.
  
  
  OBJECTIVE
  The aim of this study is to compute birth size percentiles for Italian very preterm singleton infants and assess relationship with hospital mortality.
  
  
  METHODS
  Prospective area-based cohort study.
  
  
  METHODS
  All singleton Italian infants with gestational age 22-31 weeks admitted to neonatal care in 6 Italian regions (Friuli Venezia-Giulia, Lombardia, Marche, Tuscany, Lazio and Calabria) (n. 1605).
  
  
  METHODS
  Hospital mortality.
  
  
  METHODS
  Anthropometric reference charts were derived, separately for males and females, using the lambda (λ) mu (μ) and sigma (σ) method (LMS). Logistic regression analysis was used to estimate mortality rates by gestational age and birth weight centile class, adjusting for sex, congenital anomalies and region.
  
  
  RESULTS
  At any gestational age, mortality decreased as birth weight centile increased, with lowest values observed between the 50th and the 89th centiles interval. Using the 75th-89th centile class as reference, adjusted mortality odds ratios were 7.94 (95% CI 4.18-15.08) below 10th centile; 3.04 (95% CI 1.63-5.65) between the 10th and 24th; 1.96 (95% CI 1.07-3.62) between the 25th and the 49th; 1.25 (95% CI 0.68-2.30) between the 50(h) and the 74th; and 2.07 (95% CI 1.01-4.25) at the 90th and above.
  
  
  CONCLUSIONS
  Compared to the reference, we found significantly increasing adjusted risk of death up to the 49th centile, challenging the usual 10th centile criterion as risk indicator. Continuous measures such as the birthweight z-score may be more appropriate to explore the relationship between growth retardation and adverse perinatal outcomes.
authors.affiliation: Unit of Epidemiology, Regional Agency For Health of Tuscany, Via Pietro Dazzi 1, 50141 Firenze, Italy. Electronic address: monica.dafre@ars.toscana.it.
authors.forename: M
authors.initials: M
authors.lastname: Da Frè
authors.affiliation: Hospital Network Planning and Research Area, Lazio Regional Health Authority, Via R. Raimondi Garibaldi 7, 00145 Roma, Italy. Electronic address: apolo@regione.lazio.it.
authors.forename: A
authors.initials: A
authors.lastname: Polo
authors.affiliation: Hospital Network Planning and Research Area, Lazio Regional Health Authority, Via R. Raimondi Garibaldi 7, 00145 Roma, Italy. Electronic address: ddilallo@regione.lazio.it.
authors.forename: D
authors.initials: D
authors.lastname: Di Lallo
authors.affiliation: Medical Directory, Bambino Gesù Children's Hospital, Viale Ferdinando Baldelli 41, 00146 Roma, Italy. Electronic address: simone.piga@opbg.net.
authors.forename: S
authors.initials: S
authors.lastname: Piga
authors.affiliation: Division of Pediatrics and Neonatology, Ospedale Versilia, Via Aurelia 335, Lido di Camaiore, 55043 Lucca, Italy. Electronic address: l.gagliardi@usl12.toscana.it.
authors.forename: L
authors.initials: L
authors.lastname: Gagliardi
authors.affiliation: Maternal and Child Health Institute, Marche University and Salesi Hospital, Via Toti 4, 60123 Ancona, Italy. Electronic address: v.carnielli@univpm.it.
authors.forename: V
authors.initials: V
authors.lastname: Carnielli
authors.affiliation: Neonatal Intensive Care Unit, Pugliese-Ciaccio Hospital, Viale Pia X 83, 88100 Catanzaro, Italy. Electronic address: s.miniaci@virgilio.it.
authors.forename: S
authors.initials: S
authors.lastname: Miniaci
authors.affiliation: Neonatal Intensive Care Unit, S. Maria della Misericordia Hospital, Piazzale S. Maria della Misericordia 15, 33100 Udine, Italy. Electronic address: macagno.franco@aoud.sanita.fvg.it.
authors.forename: F
authors.initials: F
authors.lastname: Macagno
authors.affiliation: Medical Directory, Bambino Gesù Children's Hospital, Viale Ferdinando Baldelli 41, 00146 Roma, Italy. Electronic address: lucilla.rava@opbg.net.
authors.forename: L
authors.initials: L
authors.lastname: Ravà
authors.affiliation: Medical Directory, Bambino Gesù Children's Hospital, Viale Ferdinando Baldelli 41, 00146 Roma, Italy. Electronic address: p.ferrante@inail.it.
authors.forename: P
authors.initials: P
authors.lastname: Ferrante
authors.affiliation: Medical Directory, Bambino Gesù Children's Hospital, Viale Ferdinando Baldelli 41, 00146 Roma, Italy. Electronic address: marina.cuttini@opbg.net.
authors.forename: M
authors.initials: M
authors.lastname: Cuttini
mesh_terms: D001724:Birth Weight; D005260:Female; D006801:Humans; D007223:Infant; D007226:Infant Mortality; D062071:Infant, Extremely Premature; D007231:Infant, Newborn; D007363:Intensive Care Units, Neonatal / Q000706:statistics & numerical data*; D007558:Italy; D008297:Male
keywords: Anthropometric reference charts; Hospital mortality; Small for gestational age; Very preterm neonates