title: Self-reported maternal cigarette smoke exposure during the periconceptional period and the risk for omphalocoele.
abstract: BACKGROUND
  We investigated whether maternal exposure to cigarette smoke was associated with omphalocoele and whether periconceptional folic acid modified the association.
  
  
  METHODS
  : We analysed data from the National Birth Defects Prevention Study on omphalocoele case (n = 301) and control (n = 8135) mothers for infants born from 1997 through 2007. Mothers who reported active smoking or exposure to second-hand smoke during the periconceptional period (1 month before conception to 3 months after) were considered exposed. Those who reported use of folic acid supplements during the same period were considered supplement users. Odds ratios and 95% confidence intervals were estimated using multivariable logistic regression adjusted for alcohol use, preconception body mass index, and race/ethnicity.
  
  
  RESULTS
  One hundred fifteen (38.2%) case and 2592 (31.9%) control mothers reported exposure to cigarette smoke during the periconceptional period. Adjusted odds ratios [95% confidence intervals] were 1.19 [0.94, 1.53] for any smoke exposure, 0.87 [0.54, 1.40] for active smoking, 1.38 [1.00, 1.90] for second-hand smoke exposure, and 1.16 [0.80, 1.67] for both exposures combined. No dose-response relationship was observed. Folic acid-containing supplements did not reduce the risk for omphalocoele among women with active or second-hand smoke exposure.
  
  
  CONCLUSIONS
  Self-reported active maternal smoking, with or without exposure to second-hand smoke, during the periconceptional period was not associated with omphalocoele. In contrast, there was a possible association with periconceptional exposure to second-hand smoke.
authors: Department of Pediatrics, University of Utah, Salt Lake City, UT.
authors: Marcia L
authors: ML
authors: Feldkamp
authors: Sivithee
authors: S
authors: Srisukhumbowornchai
authors: Paul A
authors: PA
authors: Romitti
authors: Richard S
authors: RS
authors: Olney
authors: Sandra D
authors: SD
authors: Richardson
authors: Lorenzo D
authors: LD
authors: Botto
mesh_terms: D000328:Adult; D019587:Dietary Supplements; D005260:Female; D005492:Folic Acid / Q000627:therapeutic use*; D006554:Hernia, Umbilical / Q000209:etiology / Q000517:prevention & control*; D006801:Humans; D007231:Infant, Newborn; D018811:Maternal Exposure; D009035:Mothers; D016017:Odds Ratio; D016742:Preconception Care; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000473:pathology*; D012307:Risk Factors; D057566:Self Report; D012907:Smoking / Q000009:adverse effects*; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D014028:Tobacco Smoke Pollution; D005492:Folic Acid
keywords: cigarette smoke; maternal smoking; omphalocoele; second-hand smoke