title: Preterm birth and multiple pregnancy in European countries participating in the PERISTAT project.
abstract: OBJECTIVE
  To compare rates of preterm birth among multiple births in European countries, to estimate their contribution to overall preterm birth rates and to explore factors which could explain differences between preterm birth rates.
  
  
  METHODS
  Analyses of data from vital statistics, birth registers or national samples of births.
  
  
  METHODS
  Eleven member states of the European Union.
  
  
  METHODS
  All live births or representative samples of births at national or regional level for the year 2000 or most recent year.
  
  
  METHODS
  Description of rates of preterm birth before 37 and 32 weeks, estimation of population attributable risks (PAR), study of associations between preterm birth rates in multiples and singletons and nonspontaneous labour using Spearman's rank correlation coefficient.
  
  
  METHODS
  Preterm birth rates, PAR, proportions of deliveries with nonspontaneous onset (caesarean sections before labour or induction of labour).
  
  
  RESULTS
  The proportion of multiple births before 37 weeks varied from 68.4% in Austria to 42.2% in the Republic of Ireland. In half of the countries, over 20% of all preterm births were attributable to multiple births. A strong association was found between the proportions of births before 37 weeks among multiple and singleton births (r= 0.81; P < 0.001). An association was observed between the rates of preterm birth and the proportions of deliveries with nonspontaneous onset among twins.
  
  
  CONCLUSIONS
  Wide variations in rates of preterm births and deliveries with nonspontaneous onset were found between countries, suggesting marked differences in clinical practice which could have long-term implications for the health of children from multiple births.
authors.affiliation: INSERM, U149, Epidemiological Research Unit on Perinatal and Women's Health, Paris and Villejuif, France. blondel@vjf.inserm.fr
authors.forename: B
authors.initials: B
authors.lastname: Blondel
authors.forename: A
authors.initials: A
authors.lastname: Macfarlane
authors.forename: M
authors.initials: M
authors.lastname: Gissler
authors.forename: G
authors.initials: G
authors.lastname: Breart
authors.forename: J
authors.initials: J
authors.lastname: Zeitlin
mesh_terms: D002585:Cesarean Section / Q000706:statistics & numerical data; D005060:Europe / Q000453:epidemiology; D005062:European Union / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D011247:Pregnancy; D011272:Pregnancy, Multiple / Q000706:statistics & numerical data*; D047928:Premature Birth / Q000453:epidemiology*; D012042:Registries