title: High or low oxygen saturation and severe retinopathy of prematurity: a meta-analysis.
abstract: BACKGROUND
  Low oxygen saturation appears to decrease the risk of severe retinopathy of prematurity (ROP) in preterm newborns when administered during the first few weeks after birth. High oxygen saturation seems to reduce the risk at later postmenstrual ages (PMAs). However, previous clinical studies are not conclusive individually.
  
  
  OBJECTIVE
  To perform a systematic review and meta-analysis to report the association between severe ROP incidence of premature infants with high or low target oxygen saturation measured by pulse oximetry.
  
  
  METHODS
  Studies were identified through PubMed and Embase literature searches through May 2009 by using the terms "retinopathy of prematurity and oxygen" or "retinopathy of prematurity and oxygen therapy." We selected 10 publications addressing the association between severe ROP and target oxygen saturation measured by pulse oximetry. Using a random-effects model we calculated the summary-effect estimate. We visually inspected funnel plots to examine possible publication bias.
  
  
  RESULTS
  Low oxygen saturation (70%-96%) in the first several postnatal weeks was associated with a reduced risk of severe ROP (risk ratio [RR]: 0.48 [95% confidence interval (CI): 0.31-0.75]). High oxygen saturation (94%-99%) at > or = 32 weeks' PMA was associated with a decreased risk for progression to severe ROP (RR: 0.54 [95% CI: 0.35-0.82]).
  
  
  CONCLUSIONS
  Among preterm infants with a gestational age of < or = 32 weeks, early low and late high oxygen saturation were associated with a reduced risk for severe ROP. We feel that a large randomized clinical trial with long-term developmental follow-up is warranted to confirm this meta-analytic result.
authors.affiliation: Division of Newborn Medicine, Floating Hospital for Children at Tufts Medical Center, Box 854, 800 Washington St, Boston, MA 02111-1526, USA. mchen4@tuftsmedicalcenter.org
authors.forename: Minghua L
authors.initials: ML
authors.lastname: Chen
authors.forename: Lei
authors.initials: L
authors.lastname: Guo
authors.forename: Lois E H
authors.initials: LE
authors.lastname: Smith
authors.forename: Christiane E L
authors.initials: CE
authors.lastname: Dammann
authors.forename: Olaf
authors.initials: O
authors.lastname: Dammann
mesh_terms: D015987:Effect Modifier, Epidemiologic; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D010092:Oximetry; D010100:Oxygen / Q000097:blood*; D012178:Retinopathy of Prematurity / Q000097:blood* / Q000453:epidemiology; D018570:Risk Assessment; D012720:Severity of Illness Index
chemical_list: D010100:Oxygen