title: The association of cerebral palsy and death with small-for-gestational-age birthweight in preterm neonates by individualized and population-based percentiles.
abstract: OBJECTIVE
  The objective of the study was to determine whether an individualized growth standard (IS) improves the identification of preterm small-for-gestational-age (SGA) neonates at risk of developing moderate/severe cerebral palsy (CP) or death.
  
  
  METHODS
  This study was a secondary analysis of data from a randomized trial of MgSO4 for the prevention of CP or death among anticipated preterm births. Singleton nonanomalous liveborns delivered before 34 weeks' were classified as SGA (less than the 10th percentile for their gestational age) by a population standard (PS) or an IS (incorporating maternal age, height, weight, parity, race/ethnicity, and neonatal sex). The primary outcome was the prediction of moderate or severe CP or death by age 2 years.
  
  
  RESULTS
  Of 1588 eligible newborns, 143 (9.4%) experienced CP (n = 33) or death (n = 110). Forty-four (2.8%) were SGA by the PS and 364 (22.9%) by the IS. All PS-SGA newborns also were identified as IS-SGA. SGA newborns by either standard had a similarly increased risk of CP or death (PS: relative risk [RR], 2.4, 95% confidence interval [CI], 1.3-4.3 vs IS: RR, 1.8, 95% CI, 1.3-2.5, respectively). The similarity of RRs remained after stratification by the MgSO4 treatment group. The IS was more sensitive (36% vs 6%, P < .001) but less specific (78% vs 98%, P < .001) for CP or death. The receiver operating characteristic curve analysis revealed a statistically lower area under the curve for the PS, although the ability of either method to predict which neonates would subsequently develop CP or death was poor (PS: 0.55, 95% CI, 0.49-0.60 vs IS: 0.59, 95% CI, 0.54-0.64, P < .001).
  
  
  CONCLUSIONS
  An individualized SGA growth standard does not improve the association with, or prediction of, CP or death by age 2 years.
authors.affiliation: Department of Obstetrics and Gynecology, Northwestern University, Chicago, IL.
authors.forename: William A
authors.initials: WA
authors.lastname: Grobman
authors.forename: Yinglei
authors.initials: Y
authors.lastname: Lai
authors.forename: Dwight J
authors.initials: DJ
authors.lastname: Rouse
authors.forename: Catherine Y
authors.initials: CY
authors.lastname: Spong
authors.forename: Michael W
authors.initials: MW
authors.lastname: Varner
authors.forename: Brian M
authors.initials: BM
authors.lastname: Mercer
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Leveno
authors.forename: Jay D
authors.initials: JD
authors.lastname: Iams
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Wapner
authors.forename: Yoram
authors.initials: Y
authors.lastname: Sorokin
authors.forename: John M
authors.initials: JM
authors.lastname: Thorp
authors.forename: Susan M
authors.initials: SM
authors.lastname: Ramin
authors.forename: Fergal D
authors.initials: FD
authors.lastname: Malone
authors.forename: Mary J
authors.initials: MJ
authors.lastname: O'Sullivan
authors.forename: Gary D V
authors.initials: GD
authors.lastname: Hankins
authors.forename: Steve N
authors.initials: SN
authors.lastname: Caritis
mesh_terms: D000328:Adult; D001724:Birth Weight; D002547:Cerebral Palsy / Q000453:epidemiology*; D005260:Female; D005317:Fetal Growth Retardation / Q000453:epidemiology; D005865:Gestational Age; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D007234:Infant, Premature; D007236:Infant, Small for Gestational Age; D008297:Male; D011247:Pregnancy; D047928:Premature Birth; D012372:ROC Curve; D018570:Risk Assessment; D055815:Young Adult
keywords: cerebral palsy; death; small for gestational age