OBJECTIVE:Ameta-analysisofpublishedrandomizedcontrolledtrialsinvestigatingthelongtermeffectofdexamethasoneonthenervoussystemofpreterminfants.DATASOURCES:OnlineliteratureretrievalwasconductedusingTheCochraneLibrary(fromJanuary1993toJune2013),EMBASE(fromJanuary1980toJune2013),MEDLINE(fromJanuary1963toJune2013),OVID(fromJanuary1993toJune2013),Springer(fromJanuary1994toJune2013)andChineseAcademicJournalFull-textDatabase(fromJanuary1994toJune2013).KeywordswerepreterminfantsanddexamethasoneinEnglishandChinese.STUDYSELECTION:Selectedstudieswererandomizedcontrolledtrialsassessingtheeffectofintravenousdexamethasoneinpreterminfants.Thequalityoftheincludedpaperswasevaluatedandthosewithoutthedevelopmentofthenervoussystemandanimalexperimentswereexcluded.QualityassessmentwasperformedthroughbiasriskevaluationinaccordancewithCochraneHandbook5.1.0softwareintheCochraneCollaboration.ThehomogeneousstudieswereanalyzedandcomparedusingRevman5.2.6software,andtheneffectmodelwasselectedandanalyzed.Thosepapersfailedtobeincludedinthemeta-analysisweresubjectedtodescriptiveanalysis.MAINOUTCOMEMEASURES:Nervoussysteminjuryinpreterminfants.RESULTS:Tenrandomizedcontrolledtrialswerescreened,involving1,038subjects.Amongthem512casesreceiveddexamethasonetreatmentwhile526casesservedasplacebocontrolgroupandblankcontrolgroup.Meta-analysisresultsshowedthattheincidenceofcerebralpalsy,visualimpairmentandhearinglossinpreterminfantsafterdexamethasonetreatmentwithin7daysafterbirthwassimilartothatinthecontrolgroup(RR=1.47,95%CI:0.97–2.21;RR=1.46,95%CI:0.97–2.20;RR=0.80,95%CI:0.54–1.18;P>0.05),butintelligencequotientwassignificantlydecreasedcomparedwiththecontrolgroup(MD=-3.55,95%CI:-6.59to-0.51;P=0.02).Preterminfantstreatedwithdexamethasone7daysafterbirthdemonstratedaninci
