title: Maternal socioeconomic status and the risk of congenital heart defects in offspring: a meta-analysis of 33 studies.
abstract: BACKGROUND
  We conducted this meta-analysis to address the open question of a possible association between maternal socioeconomic status and congenital heart defects (CHDs).
  
  
  METHODS
  We searched MEDLINE and EMBASE from their inception to January 1, 2014 for case-control and cohort studies that assessed the association between maternal socioeconomic status and the risk of CHDs. Study-specific relative risk estimates were polled according to random-effect or fixed-effect models.
  
  
  RESULTS
  From 3343 references, a total of 31 case-control studies and 2 cohort studies were enrolled in this meta-analysis, including more than 50,000 cases. We observed that maternal educational attainment, family income and maternal occupation were negatively associated with an 11% (pooled RR = 1.11, 95% CI: 1.03, 1.21), 5% (pooled RR = 1.05, 95% CI: 1.01, 1.09) and 51% (pooled RR = 1.51, 95% CI: 1.02, 2.24) increased risk of CHDs, respectively. In a subgroup analysis by geographic region, the results were inconsistent for the European region (RR = 1.29, 95% CI: 0.99-1.69) and USA/Canada region (RR = 1.06, 95% CI: 0.97, 1.16) in maternal educational attainment.
  
  
  CONCLUSIONS
  In summary, this meta-analysis suggests that a lower degree of maternal socioeconomic status is modestly associated with an increased risk of CHDs. However, further investigations are needed to confirm the association.
authors.affiliation: Department of Cardiothoracic Surgery, Nanjing Children's Hospital, Nanjing Medical University, Nanjing, China.
authors.forename: Di
authors.initials: D
authors.lastname: Yu
authors.affiliation: Department of Cardiothoracic Surgery, Nanjing Children's Hospital, Nanjing Medical University, Nanjing, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Feng
authors.affiliation: Department of Cardiothoracic Surgery, Nanjing Children's Hospital, Nanjing Medical University, Nanjing, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Cardiothoracic Surgery, Nanjing Children's Hospital, Nanjing Medical University, Nanjing, China.
authors.forename: Min
authors.initials: M
authors.lastname: Da
authors.affiliation: Department of Cardiothoracic Surgery, Nanjing Children's Hospital, Nanjing Medical University, Nanjing, China.
authors.forename: Changfeng
authors.initials: C
authors.lastname: Fan
authors.affiliation: Department of Cardiothoracic Surgery, Nanjing Children's Hospital, Nanjing Medical University, Nanjing, China.
authors.forename: Song
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Cardiothoracic Surgery, Nanjing Children's Hospital, Nanjing Medical University, Nanjing, China.
authors.forename: Xuming
authors.initials: X
authors.lastname: Mo
mesh_terms: D016022:Case-Control Studies; D015331:Cohort Studies; D004198:Disease Susceptibility; D005260:Female; D006330:Heart Defects, Congenital / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D018811:Maternal Exposure; D016017:Odds Ratio; D012306:Risk; D012307:Risk Factors; D012923:Social Class