title: Fetal growth, maternal prenatal smoking, and risk of invasive meningococcal disease: a nationwide case-control study.
abstract: BACKGROUND
  The prenatal period may be important for susceptibility to infections. We evaluated whether low birthweight, prematurity, and prenatal maternal smoking were associated with increased risk of invasive meningococcal disease.
  
  
  METHODS
  We linked the Danish nationwide National Registry of Patients, the Birth Registry, and social registries to obtain data on fetal growth and social factors on 1921 cases of meningococcal disease hospitalized between 1 January, 1980 and 31 December, 1999 (median age 31 months, interquartiles 13-65 months) and 37 451 population controls. The impact of maternal smoking was examined in a subsample of 462 cases and 9240 controls born after 1990, when data on smoking became available in the Birth Registry.
  
  
  RESULTS
  The adjusted odds ratios (OR) of meningococcal disease associated with low birthweight (<2500 g) varied between 1.6 (95% CI: 1.1, 2.3) in infants <12 months to 1.5 (95% CI: 1.0, 2.3) in children >60 months of age at hospitalization for meningococcal disease. Premature children had an increased risk of meningococcal disease during the first year of life only (adjusted OR = 1.3, 95% CI: 1.1, 1.9). The effect of low birthweight was very similar among mature and premature children. The adjusted OR for maternal smoking was 1.8 (95% CI: 1.4, 2.2).
  
  
  CONCLUSIONS
  Low birthweight is associated with an increased risk of meningococcal disease throughout childhood, while an effect of prematurity persists only for 12 months. Maternal prenatal smoking was associated with the risk of meningococcal disease.
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Vennelyst Boulevard 6, Bldg. 260, 8000 Aarhus C, Denmark. hts@soci.au.dk
authors.forename: Henrik Toft
authors.initials: HT
authors.lastname: Sørensen
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Labouriau
authors.forename: Elise Snitker
authors.initials: ES
authors.lastname: Jensen
authors.forename: Preben Bo
authors.initials: PB
authors.lastname: Mortensen
authors.forename: Henrik Carl
authors.initials: HC
authors.lastname: Schønheyder
mesh_terms: D016022:Case-Control Studies; D002648:Child; D005260:Female; D047109:Fetal Development; D006801:Humans; D007223:Infant; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007234:Infant, Premature; D007236:Infant, Small for Gestational Age; D008589:Meningococcal Infections / Q000453:epidemiology*; D016017:Odds Ratio; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D012306:Risk; D012907:Smoking