title: Early growth of preterm infants with prolonged hospitalisation.
abstract: BACKGROUND
  This study aimed to determine the early growth patterns of preterm infants who required prolonged hospitalisation in terms of body weight Z-score, and to explore the influencing factors and predictors of their growth.
  
  
  METHODS
  The criteria of enrolment included preterm birth, singleton pregnancy, hospitalisation within the first 24 hours of life, hospital stay ≥ 28 days and clinical follow-up beyond 91 days of corrected age. Body weight Z-scores and the incidence of underweight infants were reviewed periodically, and the influencing factors and possible predictors of growth analysed.
  
  
  RESULTS
  Body weight Z-scores of all infants of gestational age (GA) groups kept decreasing, with a trough seen at 36 weeks corrected gestational age (CGA). At corrected full-term, body weight Z-scores for all birth weight groups achieved birth level and were higher than that at 36 weeks CGA. Body weight Z-scores at 61 days corrected age was (-0.300 × GA [weeks] + 0.210 × birth weight [g] + 0.682 × body weight Z-score) at 40 weeks CGA. The cut-off values for body weight Z-score at birth (cut-off, -1.79; sensitivity, 100%; specificity, 91.3%) and 61 days corrected age (cut-off, -1.95; sensitivity, 100%; specificity, 97.1%) were selected to predict the risk of being underweight at 183 days corrected age.
  
  
  CONCLUSIONS
  Early growth restriction is a practical problem in preterm infants with prolonged hospitalisation. Body weight Z-scores at 40 weeks CGA and 61 days corrected age can be used to predict body weight gain prior to 183 days corrected age in these infants.
authors.affiliation: Department of Paediatrics, Peking University First Hospital, Beijing, China.
authors.forename: Xi-Fang
authors.initials: XF
authors.lastname: Ru
authors.forename: Qi
authors.initials: Q
authors.lastname: Feng
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.forename: Xing
authors.initials: X
authors.lastname: Li
authors.forename: Jing-Wen
authors.initials: JW
authors.lastname: Meng
authors.forename: Zai-Chen
authors.initials: ZC
authors.lastname: Guo
mesh_terms: D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D006130:Growth Disorders / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D007234:Infant, Premature / Q000254:growth & development*; D007235:Infant, Premature, Diseases / Q000453:epidemiology* / Q000209:etiology; D007902:Length of Stay / Q000639:trends*; D008297:Male; D011247:Pregnancy; D012189:Retrospective Studies; D012846:Singapore / Q000453:epidemiology