title: [Socio-economic factors associated with preterm delivery. Results of the European project in Spain].
abstract: OBJECTIVE
  The objectives of this paper were to analyse the effect of social, personal and medical risk factors on preterm birth (moderate versus very preterm) or on two preterm birth groups (spontaneous versus indicated).
  
  
  METHODS
  Results from the Spanish collaborating centre of the European multicentre case-control study EUROPOP (European Program of Occupational Risks and Pregnancy Outcome) are presented. All preterm births (529) between 22 and 36 completed weeks of amenorrhea and 788 births of 37 or more completed weeks of amenorrhea (control group) are included. Explicative variables are divided in social, personal and medical factors. A univariate and multivariate analysis by means of a logistic regression were carried out.
  
  
  RESULTS
  Very preterm birth risk was higher for women over 34 years, adjusted OR: 2.53 (1.42-4.52), with lower educational level, adjusted OR: 1.79 (1.07-2.98), for primigravid women or multigravid women with only first trimestre abortion, adjusted OR: 1.86 (1.13-3.04), and for multigravid women with previous preterm birth or second trimestre abortion, adjusted OR: 5.53 (2.97-10.35). A similar trend was observed for moderate preterm birth. Probability of spontaneous preterm birth was higher for mother over 34 years, adjusted OR: 1.51 (1.01-2.26), with lower income, adjusted OR: 1.75 (1.07-2.88) and for multigravid women with previous preterm birth or second trimestre abortion, adjusted OR: 2.96 (1.86-4.71). Results were similar for indicated preterm birth.
  
  
  CONCLUSIONS
  Social differences were found to be related to moderate and very preterm birth. No differences were observed between risk factors and kind of preterm birth: spontaneous or indicated.
authors.affiliation: Escuela Valenciana de Estudios para la Salud (EVES). Conselleria de Sanitat-Generalitat Valenciana.
authors.forename: V
authors.initials: V
authors.lastname: Escribà-Agüir
authors.forename: I
authors.initials: I
authors.lastname: Clemente
authors.forename: M
authors.initials: M
authors.lastname: Saurel-Cubizolles
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007752:Obstetric Labor, Premature / Q000453:epidemiology*; D011247:Pregnancy; D012307:Risk Factors; D012959:Socioeconomic Factors; D013030:Spain / Q000453:epidemiology; D055815:Young Adult