title: Postnatal catch-up fat after late preterm birth.
abstract: BACKGROUND
  Late preterm birth accounts for 70% of preterm births. The aim of the study was to investigate the postnatal weight gain and weight gain composition changes in a cohort of late preterm infants.
  
  
  METHODS
  A total of 49 late preterm infants (mean birth weight 2,496 ± 330 g and gestational age 35.2 ± 0.7 wks) underwent growth and body composition assessment by an air displacement plethysmography system on the fifth day of life, at term, and at 1 and 3 mo of corrected age. The reference group was composed of 40 healthy, full-term, breast-fed infants.
  
  
  RESULTS
  The late preterm infants showed a Δ fat mass gain between birth and term-corrected age equal to 182%. As compared with full-term infants, at term and 1 mo of corrected age mean weight (3,396 ± 390 vs. 3,074 ± 409 g and 4,521 ± 398 vs. 4,235 ± 673 g, respectively) and percentage of fat mass (16.1 ± 4.6 vs. 8.9 ± 2.9 and 22.6 ± 4.2 vs. 17.4 ± 4.0, respectively) were significantly higher in late preterm infants, whereas no difference among groups was found at 3 mo.
  
  
  CONCLUSIONS
  Rapid postnatal catch-up fat was found in these infants. Further studies are needed to investigate whether this short-term increase in fat mass may modulate the risk of chronic diseases or represent an adaptive mechanism to extrauterine life.
authors.affiliation: Neonatal Intensive Care Unit, Department of Clinical Sciences and Community Health, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Università degli Studi, Milano, Italy.
authors.forename: Maria L
authors.initials: ML
authors.lastname: Giannì
authors.forename: Paola
authors.initials: P
authors.lastname: Roggero
authors.forename: Nadia
authors.initials: N
authors.lastname: Liotto
authors.forename: Orsola
authors.initials: O
authors.lastname: Amato
authors.forename: Pasqua
authors.initials: P
authors.lastname: Piemontese
authors.forename: Daniela
authors.initials: D
authors.lastname: Morniroli
authors.forename: Beatrice
authors.initials: B
authors.lastname: Bracco
authors.forename: Fabio
authors.initials: F
authors.lastname: Mosca
mesh_terms: D000273:Adipose Tissue / Q000254:growth & development*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature