title: Educational inequalities in preterm and term small-for-gestational-age birth over time.
abstract: OBJECTIVE
  Time trends in educational inequalities in small-for-gestational-age (SGA) birth are important to evaluate for policy, especially at preterm gestational ages when morbidity and mortality are typically greater. We evaluated educational inequalities in preterm and term SGA birth over time, accounting for potential bias at preterm gestational ages.
  
  
  METHODS
  Data included 2,204,056 singleton live births from 25 to 43 gestational weeks, 1981 to 2007. We estimated prevalence ratios (PR) and percent prevalence differences (PPD) of preterm and term SGA birth for a continuous education score, accounting for maternal characteristics. Sensitivity analyses included correction for misclassification of preterm SGA status, and use of fetuses-at-risk denominators in regression models.
  
  
  RESULTS
  Although prevalence of SGA birth decreased over time, relative educational inequalities (PRs) persisted for preterm and term cases. PPDs decreased slightly, but more for term than preterm SGA birth. Sensitivity analyses indicated that PRs for education were stronger for preterm than term SGA birth. PPDs were larger for term SGA birth in the first period, but greater for preterm SGA birth in the last period.
  
  
  CONCLUSIONS
  Relative educational inequalities in SGA birth persisted over time. The difference in prevalence between the least and most educated mothers is currently greater for preterm than for term SGA birth.
authors.affiliation: Institut national de santé publique du Québec, 190 boulevard Crémazie Est, Montréal, Québec, Canada. nathalie.auger@inspq.qc.ca
authors.forename: Nathalie
authors.initials: N
authors.lastname: Auger
authors.forename: Alison L
authors.initials: AL
authors.lastname: Park
authors.forename: Sam
authors.initials: S
authors.lastname: Harper
authors.forename: Mark
authors.initials: M
authors.lastname: Daniel
authors.forename: Federico
authors.initials: F
authors.lastname: Roncarolo
authors.forename: Robert W
authors.initials: RW
authors.lastname: Platt
mesh_terms: D000328:Adult; D001719:Birth Certificates; D004522:Educational Status; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007236:Infant, Small for Gestational Age; D017533:Marital Status; D008423:Maternal Age; D009035:Mothers / Q000193:education* / Q000706:statistics & numerical data; D011792:Quebec; D055815:Young Adult