title: Proportion of selected congenital heart defects attributable to recognized risk factors.
abstract: To assess the contribution of multiple risk factors for two congenital heart defects-hypoplastic left heart syndrome (HLHS) and tetralogy of Fallot (TOF).
  
  
  
  We used data from the National Birth Defects Prevention Study (1997-2011) to estimate average adjusted population attributable fractions for several recognized risk factors, including maternal prepregnancy overweight-obesity, pregestational diabetes, age, and infant sex.
  
  
  
  There were 594 cases of isolated simple HLHS, 971 cases of isolated simple TOF, and 11,829 controls in the analysis. Overall, 57.0% of HLHS cases and 37.0% of TOF cases were estimated to be attributable to risk factors included in our model. Among modifiable HLHS risk factors, maternal prepregnancy overweight-obesity accounted for the largest proportion of cases (6.5%). Among modifiable TOF risk factors, maternal prepregnancy overweight-obesity and maternal age of 35 years or older accounted for the largest proportions of cases (8.3% and 4.3%, respectively).
  
  
  
  Approximately half of HLHS cases and one-third of TOF cases were estimated to be attributable to risk factors included in our models. Interventions targeting factors that can be modified may help reduce the risk of HLHS and TOF development. Additional research into the etiology of HLHS and TOF may reveal other modifiable risk factors that might contribute to primary prevention efforts.
authors.affiliation: Division of Congenital and Developmental Disorders, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, GA. Electronic address: rsimeone@cdc.gov.
authors.forename: Regina M
authors.initials: RM
authors.lastname: Simeone
authors.affiliation: Division of Congenital and Developmental Disorders, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, GA.
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Tinker
authors.affiliation: Division of Congenital and Developmental Disorders, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, GA.
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: Gilboa
authors.affiliation: Division of Epidemiology, Human Genetics and Environmental Sciences, University of Texas School of Public Health, Houston, TX.
authors.forename: A J
authors.initials: AJ
authors.lastname: Agopian
authors.affiliation: Division of Congenital and Developmental Disorders, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, GA; Department of Pediatrics, Children's Healthcare of Atlanta, Emory University School of Medicine, Atlanta, GA.
authors.forename: Matthew E
authors.initials: ME
authors.lastname: Oster
authors.affiliation: Division of Congenital and Developmental Disorders, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, GA; Carter Consulting, Atlanta, GA.
authors.forename: Owen J
authors.initials: OJ
authors.lastname: Devine
authors.affiliation: Division of Congenital and Developmental Disorders, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, GA.
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Honein
mesh_terms: D016022:Case-Control Studies; D005260:Female; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000209:etiology*; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D012307:Risk Factors; D013771:Tetralogy of Fallot / Q000209:etiology*; D014481:United States
keywords: Heart defects, congenital; Hypoplastic left heart syndrome; Population attributable fraction; Tetralogy of Fallot