title: Maternal prepregnancy body mass index and risk of neural tube defects: A population-based case-control study in Shanxi province, China.
abstract: BACKGROUND
  Many studies from the Western world have indicated that maternal obesity is associated with an increased risk of neural tube defects (NTDs). However, few reports have been available on this association from Asian populations. Our aim was to examine the relationship between maternal prepregnancy body mass index (BMI) and the risk of NTDs in a population of northern China.
  
  
  METHODS
  Data were derived from an ongoing population-based case-control study of birth defects in Shanxi province, China. Subjects were 511 NTD cases and 687 controls selected from the same population between January 2003 and June 2007. BMI was based on maternal height and prepregnancy weight as reported within 1 week of delivery.
  
  
  RESULTS
  We found no significantly increased risk of NTDs for obese women (adjusted odds ratio [OR], 0.65; 95% confidence interval [CI], 0.29-1.49) or for underweight women (adjusted OR, 1.00; 95% CI, 0.62-1.62) relative to normal-weight women. We found a significantly reduced risk of overall NTDs (adjusted OR, 0.56; 95% CI, 0.41-0.76) and anencephaly (adjusted OR, 0.40; 95% CI, 0.26-0.62) for overweight women compared to normal-weight women.
  
  
  CONCLUSIONS
  Our results do not support the association between maternal prepregnancy obesity and increased risk of overall NTDs or of any subtype of NTDs in the Chinese population.
authors.affiliation: Institute of Reproductive and Child Health, Peking University Health Science Center, Beijing, China.
authors.forename: Zhiwen
authors.initials: Z
authors.lastname: Li
authors.forename: Jianmeng
authors.initials: J
authors.lastname: Liu
authors.forename: Rongwei
authors.initials: R
authors.lastname: Ye
authors.forename: Le
authors.initials: L
authors.lastname: Zhang
authors.forename: Lijun
authors.initials: L
authors.lastname: Pei
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Zheng
authors.forename: Aiguo
authors.initials: A
authors.lastname: Ren
mesh_terms: D000328:Adult; D015992:Body Mass Index; D016022:Case-Control Studies; D002681:China; D005260:Female; D006801:Humans; D009436:Neural Tube Defects / Q000209:etiology*; D009765:Obesity / Q000150:complications*; D016017:Odds Ratio; D012307:Risk Factors