title: Maternal cell phone use during pregnancy and child behavioral problems in five birth cohorts.
abstract: Previous studies have reported associations between prenatal cell phone use and child behavioral problems, but findings have been inconsistent and based on retrospective assessment of cell phone use. This study aimed to assess this association in a multi-national analysis, using data from three cohorts with prospective data on prenatal cell phone use, together with previously published data from two cohorts with retrospectively collected cell phone use data.
  
  
  
  We used individual participant data from 83,884 mother-child pairs in the five cohorts from Denmark (1996-2002), Korea (2006-2011), the Netherlands (2003-2004), Norway (2004-2008), and Spain (2003-2008). We categorized cell phone use into none, low, medium, and high, based on frequency of calls during pregnancy reported by the mothers. Child behavioral problems (reported by mothers using the Strengths and Difficulties Questionnaire or Child Behavior Checklist) were classified in the borderline/clinical and clinical ranges using validated cut-offs in children aged 5-7years. Cohort specific risk estimates were meta-analyzed.
  
  
  
  Overall, 38.8% of mothers, mostly from the Danish cohort, reported no cell phone use during pregnancy and these mothers were less likely to have a child with overall behavioral, hyperactivity/inattention or emotional problems. Evidence for a trend of increasing risk of child behavioral problems through the maternal cell phone use categories was observed for hyperactivity/inattention problems (OR for problems in the clinical range: 1.11, 95%CI 1.01, 1.22; 1.28, 95%CI 1.12, 1.48, among children of medium and high users, respectively). This association was fairly consistent across cohorts and between cohorts with retrospectively and prospectively collected cell phone use data.
  
  
  
  Maternal cell phone use during pregnancy may be associated with an increased risk for behavioral problems, particularly hyperactivity/inattention problems, in the offspring. The interpretation of these results is unclear as uncontrolled confounding may influence both maternal cell phone use and child behavioral problems.
authors.affiliation: ISGlobal Center for Research in Environmental Epidemiology, Doctor Aiguader 88, 08003 Barcelona, Spain; Pompeu Fabra University, Carrer Ramon Trias Fargas, 25-27, 08005 Barcelona, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Instituto de Salud Carlos III, Av. Monforte de Lemos, 3-5, Madrid, Spain. Electronic address: laura.birks@isglobal.org.
authors.forename: Laura
authors.initials: L
authors.lastname: Birks
authors.affiliation: ISGlobal Center for Research in Environmental Epidemiology, Doctor Aiguader 88, 08003 Barcelona, Spain; Pompeu Fabra University, Carrer Ramon Trias Fargas, 25-27, 08005 Barcelona, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Instituto de Salud Carlos III, Av. Monforte de Lemos, 3-5, Madrid, Spain; Department of Child and Adolescent Psychiatry/Psychology, Erasmus University Medical Centre-Sophia Children's Hospital, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands.
authors.forename: Mònica
authors.initials: M
authors.lastname: Guxens
authors.affiliation: Domain of Infection Control and Environmental Health, Norwegian Institute of Public Health, Lovisenberggata 8, 0456 Oslo, Norway.
authors.forename: Eleni
authors.initials: E
authors.lastname: Papadopoulou
authors.affiliation: Domain of Infection Control and Environmental Health, Norwegian Institute of Public Health, Lovisenberggata 8, 0456 Oslo, Norway.
authors.forename: Jan
authors.initials: J
authors.lastname: Alexander
authors.affiliation: Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Instituto de Salud Carlos III, Av. Monforte de Lemos, 3-5, Madrid, Spain; Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Av. De Blasco Ibáñez, 13, 46010, Valencia, Spain.
authors.forename: Ferran
authors.initials: F
authors.lastname: Ballester
authors.affiliation: Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Instituto de Salud Carlos III, Av. Monforte de Lemos, 3-5, Madrid, Spain; Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Av. De Blasco Ibáñez, 13, 46010, Valencia, Spain.
authors.forename: Marisa
authors.initials: M
authors.lastname: Estarlich
authors.affiliation: BIODONOSTIA Health Research Institute, Begiristain Doctorea Pasealekua, 20014 San Sebastian, Spain; University of the Basque Country (UPV/EHU), Faculty of Medicine, Barrio Sarriena, s/n, 48940 Leioa, Spain.
authors.forename: Mara
authors.initials: M
authors.lastname: Gallastegi
authors.affiliation: Department of Preventive Medicine, Dankook University, College of Medicine, 152 Jukjeon-ro, Jukjeon 1, Cheonan, Republic of Korea.
authors.forename: Mina
authors.initials: M
authors.lastname: Ha
authors.affiliation: Department of Exposure and Risk Assessment, Norwegian Institute of Public Health, Lovisenberggata 8, 0456 Oslo, Norway.
authors.forename: Margaretha
authors.initials: M
authors.lastname: Haugen
authors.affiliation: Institute for Risk Assessment Sciences, Utrecht University, Domplein 29, 3512 JE Utrecht, Netherlands.
authors.forename: Anke
authors.initials: A
authors.lastname: Huss
authors.affiliation: Department of Epidemiology, School of Public Health, University of California, 650 Charles E Young Dr S, Los Angeles, CA 90095, USA; Danish Epidemiology Science Centre, Department of Public Health, Aarhus University, Aarhus, Denmark.
authors.forename: Leeka
authors.initials: L
authors.lastname: Kheifets
authors.affiliation: Department of Preventive Medicine, Dankook University, College of Medicine, 152 Jukjeon-ro, Jukjeon 1, Cheonan, Republic of Korea.
authors.forename: Hyungryul
authors.initials: H
authors.lastname: Lim
authors.affiliation: Danish Epidemiology Science Centre, Department of Public Health, Aarhus University, Nordre Ringgade 1, 8000 Aarhus, Denmark.
authors.forename: Jørn
authors.initials: J
authors.lastname: Olsen
authors.affiliation: Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Instituto de Salud Carlos III, Av. Monforte de Lemos, 3-5, Madrid, Spain; BIODONOSTIA Health Research Institute, Begiristain Doctorea Pasealekua, 20014 San Sebastian, Spain; Public Health Division of Gipuzkoa, Basque Government, De Francia Ibilbidea, 12, 20012 San Sebastian, Spain.
authors.forename: Loreto
authors.initials: L
authors.lastname: Santa-Marina
authors.affiliation: Department of Epidemiology, School of Public Health, University of California, 650 Charles E Young Dr S, Los Angeles, CA 90095, USA; Danish Epidemiology Science Centre, Department of Public Health, Aarhus University, Nordre Ringgade 1, 8000 Aarhus, Denmark; Danish Epidemiology Science Centre, Department of Public Health, Aarhus University, Aarhus, Denmark.
authors.forename: Madhuri
authors.initials: M
authors.lastname: Sudan
authors.affiliation: Institute for Risk Assessment Sciences, Utrecht University, Domplein 29, 3512 JE Utrecht, Netherlands; Julius Center for Health Sciences and Primary Care, University Medical Center, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
authors.forename: Roel
authors.initials: R
authors.lastname: Vermeulen
authors.affiliation: Department of Public Health, Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
authors.forename: Tanja
authors.initials: T
authors.lastname: Vrijkotte
authors.affiliation: ISGlobal Center for Research in Environmental Epidemiology, Doctor Aiguader 88, 08003 Barcelona, Spain; Pompeu Fabra University, Carrer Ramon Trias Fargas, 25-27, 08005 Barcelona, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Instituto de Salud Carlos III, Av. Monforte de Lemos, 3-5, Madrid, Spain.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Cardis
authors.affiliation: ISGlobal Center for Research in Environmental Epidemiology, Doctor Aiguader 88, 08003 Barcelona, Spain; Pompeu Fabra University, Carrer Ramon Trias Fargas, 25-27, 08005 Barcelona, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Instituto de Salud Carlos III, Av. Monforte de Lemos, 3-5, Madrid, Spain.
authors.forename: Martine
authors.initials: M
authors.lastname: Vrijheid
mesh_terms: D000075782:Cell Phone Use / Q000706:statistics & numerical data*; D002648:Child; D002675:Child, Preschool; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D001523:Mental Disorders / Q000453:epidemiology; D009035:Mothers / Q000706:statistics & numerical data*; D009426:Netherlands / Q000453:epidemiology; D009664:Norway / Q000453:epidemiology; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology*; D000066553:Problem Behavior; D011446:Prospective Studies; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D013030:Spain / Q000453:epidemiology
keywords: Attention deficit disorder with hyperactivity; Cell phones; Child behavior; Child health; Electromagnetic radiation; Pregnancy