title: Validity of retrospectively reported behaviors during the periconception window.
abstract: OBJECTIVE
  To assess the validity of retrospectively reported maternal behaviors while attempting pregnancy.
  
  
  METHODS
  Participants in a prospective pregnancy cohort study with periconception enrollment were queried about use of cigarettes, alcohol, vitamins and caffeine and the consumption of sport fish while attempting pregnancy. Prospective longitudinal data reported in daily diaries (gold standard) were compared with data obtained a decade later using a self-administered questionnaire. Agreement was assessed by percent agreement and Kappa coefficients.
  
  
  RESULTS
  Among the 82 participating women, percent agreement ranged from 54-74% for the 5 behaviors. Validity was highest for smoking (Kappa = 0.43, 95% confidence interval [CI]: 0.22, 0.65) followed by fish consumption (Kappa = 0.32, 95% CI: 0.09, 0.55), caffeine (Kappa = 0.21, 95% CI: 0.09, 0.51) and alcohol (Kappa = 0.20, 95% CI: 0.08, 0.33). There were no systematic differences in agreement by time to pregnancy or pregnancy outcome. Associations between smoking and alcohol consumption and pregnancy outcomes were highly sensitive to the levels of misclassification observed in this study.
  
  
  CONCLUSIONS
  Validity was poor to moderate for the 5 behaviors, though higher for more regular behaviors such as smoking and caffeine consumption. The potential for misreporting of periconception behaviors can affect inferences, and thus efforts to capture information prospectively should be promoted.
authors.affiliation: Division of Epidemiology, Statistics and Prevention Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland. USA. agollenb@su.edu
authors.forename: Audra L
authors.initials: AL
authors.lastname: Gollenberg
authors.forename: Sunni L
authors.initials: SL
authors.lastname: Mumford
authors.forename: Maureen A
authors.initials: MA
authors.lastname: Cooney
authors.forename: Rajeshwari
authors.initials: R
authors.lastname: Sundaram
authors.forename: Germaine M Buck
authors.initials: GM
authors.lastname: Louis
mesh_terms: D000428:Alcohol Drinking; D000818:Animals; D001519:Behavior; D002110:Caffeine / Q000008:administration & dosage; D004032:Diet; D005260:Female; D005306:Fertilization / Q000502:physiology*; D005399:Fishes; D006801:Humans; D008019:Life Style; D011247:Pregnancy; D011256:Pregnancy Outcome; D015203:Reproducibility of Results; D012189:Retrospective Studies; D057566:Self Report; D012907:Smoking; D014815:Vitamins / Q000008:administration & dosage
chemical_list: D014815:Vitamins; D002110:Caffeine