title: Health consequences of prophylactic exposure to antenatal corticosteroids among children born late preterm or term.
abstract: OBJECTIVE
  To investigate the duration of effects and health consequences of earlier antenatal corticosteroid exposure in infants born late preterm or term.
  
  
  METHODS
  Observational cohort study.
  
  
  METHODS
  Children born after gestational week 34 in Sweden, 1976-1997, whose mothers were hospitalized for imminent preterm delivery. The children were followed to their 11th birthday.
  
  
  METHODS
  The cohort consisted of 11 873 infants, of whom 8620 were exposed.
  
  
  METHODS
  Exposure was estimated at hospital level. Infants born at a hospital practicing antenatal corticosteroid administration were classified as exposed. Estimation of hospital routines was based on questionnaire data, telephone interviews with physicians and pharmacy sales, validated in a random sample of medical records. Logistic regression was used to assess associations with adjustments for pregnancy length, birth year and hospital level.
  
  
  METHODS
  Rates and odds ratios of mortality, respiratory distress syndrome, bronchopulmonary dysplasia, epilepsy, cerebral palsy, childhood diabetes, birthweight, length and head circumference for all infants, and for preterm and term infants, respectively.
  
  
  RESULTS
  Exposed infants had reduced risks of respiratory distress syndrome (odds ratio 0.54, 95% confidence interval 0.35-0.83) and small head circumference (odds ratio 0.47, 95% confidence interval 0.36-0.61), and an increased risk of low Apgar scores (odds ratio 1.40, 95% confidence interval 1.01-1.94), most pronounced in infants born after gestational week 37.
  
  
  CONCLUSIONS
  Infants born after gestational week 34 seem to benefit from earlier antenatal corticosteroid administration, with reduced risks of respiratory distress syndrome. However, the treatment was less beneficial for term infants, because they also had increased risk of low Apgar scores.
authors.affiliation: Centre for Pharmacoepidemiology, Karolinska Institutet, Stockholm, Sweden. lena.eriksson.2@ki.se
authors.forename: Lena
authors.initials: L
authors.lastname: Eriksson
authors.forename: Bengt
authors.initials: B
authors.lastname: Haglund
authors.forename: Uwe
authors.initials: U
authors.lastname: Ewald
authors.forename: Viveca
authors.initials: V
authors.lastname: Odlind
authors.forename: Helle
authors.initials: H
authors.lastname: Kieler
mesh_terms: D000305:Adrenal Cortex Hormones / Q000009:adverse effects* / Q000627:therapeutic use*; D001034:Apgar Score; D002648:Child; D002675:Child, Preschool; D005260:Female; D005317:Fetal Growth Retardation / Q000139:chemically induced*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000517:prevention & control*; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000517:prevention & control; D007407:Interviews as Topic; D016015:Logistic Models; D008431:Maternal-Fetal Exchange; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013548:Sweden / Q000453:epidemiology
chemical_list: D000305:Adrenal Cortex Hormones