title: Exploring educational disparities in risk of preterm delivery: a comparative study of 12 European birth cohorts.
abstract: BACKGROUND
  An association between education and preterm delivery has been observed in populations across Europe, but differences in methodology limit comparability. We performed a direct cross-cohort comparison of educational disparities in preterm delivery based on individual-level birth cohort data.
  
  
  METHODS
  The study included data from 12 European cohorts from Denmark, England, France, Lithuania, the Netherlands, Norway, Italy, Portugal, and Spain. The cohorts included between 2434 and 99 655 pregnancies. The association between maternal education and preterm delivery (22-36 completed weeks of gestation) was reported as risk ratios, risk differences, and slope indexes of inequality with 95% confidence intervals (CIs).
  
  
  RESULTS
  Singleton preterm live delivery proportion varied between 3.7% and 7.5%. There were large variations between the cohorts in the distribution of education and maternal characteristics. Nevertheless, there were similar educational differences in risk of preterm delivery in 8 of the 12 cohorts with slope index of inequality varying between 2.2 [95% CI 1.1, 3.3] and 4.0 [95% CI 1.4, 6.6] excess preterm deliveries per 100 singleton deliveries among the educationally most disadvantaged, and risk ratio between the lowest and highest education category varying from 1.4 [95% CI 1.1, 1.8] to 1.9 [95% CI 1.2, 3.1]. No associations were found in the last four cohorts.
  
  
  CONCLUSIONS
  Educational disparities in preterm delivery were found all over Europe. Despite differences in the distributions of education and preterm delivery, the results were remarkably similar across the cohorts. For those few cohorts that did not follow the pattern, study and country characteristics did not explain the differences.
authors: Section of Social Medicine, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
authors: Gry
authors: G
authors: Poulsen
authors: Katrine
authors: K
authors: Strandberg-Larsen
authors: Laust
authors: L
authors: Mortensen
authors: Henrique
authors: H
authors: Barros
authors: Sylvaine
authors: S
authors: Cordier
authors: Sofia
authors: S
authors: Correia
authors: Asta
authors: A
authors: Danileviciute
authors: Manon
authors: M
authors: van Eijsden
authors: Ana
authors: A
authors: Fernández-Somoano
authors: Ulrike
authors: U
authors: Gehring
authors: Regina
authors: R
authors: Grazuleviciene
authors: Esther
authors: E
authors: Hafkamp-de Groen
authors: Tine Brink
authors: TB
authors: Henriksen
authors: Morten Søndergaard
authors: MS
authors: Jensen
authors: Isabel
authors: I
authors: Larrañaga
authors: Per
authors: P
authors: Magnus
authors: Kate
authors: K
authors: Pickett
authors: Hein
authors: H
authors: Raat
authors: Lorenzo
authors: L
authors: Richiardi
authors: Florence
authors: F
authors: Rouget
authors: Franca
authors: F
authors: Rusconi
authors: Camilla
authors: C
authors: Stoltenberg
authors: Eleonora P
authors: EP
authors: Uphoff
authors: Tanja G M
authors: TG
authors: Vrijkotte
authors: Alet H
authors: AH
authors: Wijga
authors: Martine
authors: M
authors: Vrijheid
authors: Merete
authors: M
authors: Osler
authors: Anne-Marie Nybo
authors: AM
authors: Andersen
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000009:adverse effects / Q000453:epidemiology* / Q000517:prevention & control; D015331:Cohort Studies; D004522:Educational Status; D005060:Europe / Q000453:epidemiology; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy; D047928:Premature Birth / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology*; D000074606:Smoking Prevention; D012959:Socioeconomic Factors
keywords: European pregnancy birth cohort; Health inequalities; cross-cohort collaboration; educational inequalities; preterm birth