title: Perinatal smoking exposure and behavioral problems in Japanese children aged 5 years: The Kyushu Okinawa Maternal and Child Health Study.
abstract: BACKGROUND
  Epidemiological evidence regarding the relationship between maternal secondhand smoke (SHS) exposure during pregnancy and postnatal SHS exposure and childhood behavioral problems is scarce.
  
  
  OBJECTIVE
  The present prebirth cohort study investigated the association between perinatal smoking exposure and behavioral problems in Japanese children aged 5 years.
  
  
  METHODS
  Subjects were 1200 mother-child pairs. Data on variables under study were obtained using parent questionnaires. Emotional problems, conduct problems, hyperactivity problems, and peer problems were assessed using the Strengths and Difficulties Questionnaire. Adjustment was made for maternal age, gestation at baseline, region of residence at baseline, number of children at baseline, maternal and paternal education, household income, maternal depressive symptoms during pregnancy, maternal alcohol intake during pregnancy, child's birth weight, child's sex, and breastfeeding duration.
  
  
  RESULTS
  Maternal smoking during pregnancy was independently associated with increased risk of conduct problems and hyperactivity problems (adjusted odds ratios: ORs [95% confidence intervals: CIs]=1.93 [1.15-3.17] and 1.89 [1.03-3.33], respectively). Maternal SHS exposure at work during pregnancy was independently positively related to conduct problems and hyperactivity problems (adjusted ORs [95% CI]=1.54 [1.01-2.31] and 1.69 [1.04-2.67], respectively). Smoking by any household member, and especially by the child's father, during the first year of life was independently associated with an increased risk of emotional problems (adjusted ORs [95% CI]=1.55 [1.06-2.26] and 1.63 [1.11-2.40], respectively).
  
  
  CONCLUSIONS
  Maternal smoking and maternal SHS exposure at work during pregnancy may increase the risk of conduct problems and hyperactivity problems. Smoking by any household member, and especially by the child's father, may increase the risk of emotional problems.
authors.affiliation: Department of Epidemiology and Preventive Medicine, Ehime University Graduate School of Medicine, Toon, Ehime 791-0295, Japan; Epidemiology and Medical Statistics Unit, Translational Research Center, Ehime University Hospital, Ehime, Japan. Electronic address: tanaka.keiko.jn@ehime-u.ac.jp.
authors.forename: Keiko
authors.initials: K
authors.lastname: Tanaka
authors.affiliation: Department of Epidemiology and Preventive Medicine, Ehime University Graduate School of Medicine, Toon, Ehime 791-0295, Japan; Epidemiology and Medical Statistics Unit, Translational Research Center, Ehime University Hospital, Ehime, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Miyake
authors.affiliation: Department of Epidemiology and Preventive Medicine, Ehime University Graduate School of Medicine, Toon, Ehime 791-0295, Japan; Epidemiology and Medical Statistics Unit, Translational Research Center, Ehime University Hospital, Ehime, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Furukawa
authors.affiliation: Health Tourism Research Fields, Graduate School of Tourism Sciences, University of the Ryukyus, Okinawa, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Arakawa
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D000066553:Problem Behavior; D011446:Prospective Studies; D012907:Smoking / Q000009:adverse effects*
keywords: Behavioral problems; Child; Japan; Prebirth cohort; Smoking