title: Outcomes of very-low-birthweight infants at 3 years of age born in 2003-2004 in Japan.
abstract: BACKGROUND
  The aim of this study was to describe and compare neurodevelopmental outcomes with birthweight (BW) groups at 250-g intervals of very-low-birthweight (VLBW) infants at 3 years of age in a multicenter cohort in Japan.
  
  
  METHODS
  A total of 3104 VLBW infants born in 2003 and 2004 registered in a NICU-network database were followed in the study. Neurodevelopmental impairment (NDI) was defined as any of the following impairments: cerebral palsy, unilateral or bilateral blindness, severe hearing impairment, or developmental delay; a developmental quotient (DQ) <70 measured using the Kyoto Scale of Psychological Development test or judged by physicians in infants without the test.
  
  
  RESULTS
  A total of 257 infants died and follow-up data were obtained from 1826 infants. Of the 1826 infants, 155 (8.5%) had cerebral palsy, 25 (1.4%) had visual impairment, and 12 (0.7%) had hearing impairment. Of the 1197 infants in whom DQ was measured, 184 (15.4%) had DQ < 70. The proportion of NDI in the evaluated infants was 19.2% (n= 350), ranging from 11.9% (BW 1251-1500 g) to 42.0% (BW ≤ 500 g). Odds ratios (95%CI) of NDI or death against the group BW 1251-1500 g were 20.62 (13.29-31.97) in BW ≤ 500 g, 7.25 (5.45-9.64) in BW 501-750 g, 2.85 (2.12-3.82) in BW 751-1000 g and 1.18 (0.85-1.64) in BW 1001-1250 g.
  
  
  CONCLUSIONS
  The increasing proportion of NDI or death, an indicator of adverse outcome, was associated with decrement in the BW of the groups. Although we have to consider a bias due to loss of follow-up data, the incidence of NDI was similar to previous overseas cohort studies despite the higher survival proportion in our study.
authors.affiliation: Department of Pediatrics, Jichi Medical University, Shimotsuke, Tochigi, Japan. ykono@jichi.ac.jp
authors.forename: Yumi
authors.initials: Y
authors.lastname: Kono
authors.forename: Jun
authors.initials: J
authors.lastname: Mishina
authors.forename: Naohiro
authors.initials: N
authors.lastname: Yonemoto
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kusuda
authors.forename: Masanori
authors.initials: M
authors.lastname: Fujimura
mesh_terms: D001724:Birth Weight; D002423:Cause of Death / Q000639:trends; D002657:Child Development; D002675:Child, Preschool; D002658:Developmental Disabilities / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007223:Infant; D007226:Infant Mortality / Q000639:trends; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D007363:Intensive Care Units, Neonatal; D007564:Japan / Q000453:epidemiology; D008297:Male; D016017:Odds Ratio; D011379:Prognosis; D012189:Retrospective Studies