title: Handedness in the helsinki ultrasound trial.
abstract: OBJECTIVE
  To determine whether exposure to prenatal ultrasound increases non-right-handedness in boys.
  
  
  METHODS
  The association between exposure to prenatal ultrasound and handedness was tested, using logistic regression analysis, in the Helsinki Ultrasound Trial data. We applied an intention-to-treat approach in this analysis of a subset of 4150 subjects whose parents answered a follow-up questionnaire on handedness when the children were aged 13-15 years.
  
  
  RESULTS
  The odds ratio for non-right-handedness of children who had been exposed to prenatal ultrasound was 1.16 (0.98-1.37) for all subjects, 1.12 (0.89-1.41) for boys and 1.24 (0.97-1.58) for girls.
  
  
  CONCLUSIONS
  We could not confirm the hypothesis that prenatal ultrasound exposure and handedness are associated. Our findings were independent of the particular definition of handedness used, whether it was considered according to the writing hand alone or defined using a laterality quotient.
authors.affiliation: Department of Public Health, Hjelt Institute, University of Helsinki, Helsinki, Finland. kauko.heikkila@helsinki.fi
authors.forename: K
authors.initials: K
authors.lastname: Heikkilä
authors.forename: E
authors.initials: E
authors.lastname: Vuoksimaa
authors.forename: K
authors.initials: K
authors.lastname: Oksava
authors.forename: A
authors.initials: A
authors.lastname: Saari-Kemppainen
authors.forename: M
authors.initials: M
authors.lastname: Iivanainen
mesh_terms: D000293:Adolescent; D019317:Evidence-Based Medicine; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D016017:Odds Ratio; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000175:diagnosis*; D016032:Randomized Controlled Trials as Topic; D012044:Regression Analysis; D012737:Sex Factors; D011795:Surveys and Questionnaires; D016216:Ultrasonography, Prenatal / Q000009:adverse effects*