title: Development after exposure to polychlorinated biphenyls and dichlorodiphenyl dichloroethene transplacentally and through human milk.
abstract: OBJECTIVE
  To determine whether exposure to polychlorinated biphenyls (PCBs) or dichlorodiphenyl dichloroethene (DDE), either transplacentally or through breast feeding, affected scores on the Bayley Scales of Infant Development at 6 or 12 months of age.
  
  
  METHODS
  Cohort followed from birth to 1 year of age.
  
  
  METHODS
  General community.
  
  
  METHODS
  Volunteer sample of 858 infants, of whom 802 had Bayley scores available at either 6 months or 12 months or both.
  
  
  METHODS
  None.
  
  
  RESULTS
  Bayley scales and chemical measurements were done independently. Higher transplacental exposure to PCBs was associated with lower psychomotor scores at both 6 and 12 months of age; the difference between the mean scores in the lowest and highest PCB groups was 7 points at 6 months and 8 points at 12 months. Higher transplacental exposure to DDE was associated with higher mental scores at 6 months of age (the difference between the mean scores in the lowest and highest DDE groups was 6 points), but no relationship was seen at 12 months. Exposure to either chemical through breast feeding was apparently unrelated to Bayley scores.
  
  
  CONCLUSIONS
  Transplacental exposure to PCBs was associated with lower psychomotor scores. No deleterious effects were associated with breast feeding.
mesh_terms: D001921:Brain / Q000187:drug effects; D001942:Breast Feeding; D002657:Child Development / Q000187:drug effects*; D002675:Child, Preschool; D003633:Dichlorodiphenyl Dichloroethylene / Q000009:adverse effects* / Q000032:analysis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007360:Intelligence / Q000187:drug effects; D008895:Milk, Human / Q000032:analysis*; D009483:Neuropsychological Tests; D011078:Polychlorinated Biphenyls / Q000009:adverse effects* / Q000032:analysis; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D011597:Psychomotor Performance / Q000187:drug effects
chemical_list: D003633:Dichlorodiphenyl Dichloroethylene; D011078:Polychlorinated Biphenyls