title: Maternal occupational exposure to polycyclic aromatic hydrocarbons and risk of oral cleft-affected pregnancies.
abstract: OBJECTIVE
  To evaluate whether there is an association between maternal occupational exposure to polycyclic aromatic hydrocarbons and oral clefts in offspring. This is the first human study of polycyclic aromatic hydrocarbons and clefts of which the authors are aware.
  
  
  METHODS
  Case-control study.
  
  
  METHODS
  Data for 1997 to 2002 from the National Birth Defects Prevention Study, a large population-based case-control study in the United States, were analyzed. Maternal telephone interviews yielded information on jobs held in the month before through 3 months after conception. Two industrial hygienists independently assessed occupational exposure to polycyclic aromatic hydrocarbons; all jobs rated as exposed or with rating difficulty were reviewed with a third industrial hygienist to reach consensus on all exposure parameters. Logistic regression estimated crude and adjusted odds ratios with 95% confidence intervals for cleft lip with or without cleft palate and cleft palate alone.
  
  
  RESULTS
  There were 2989 controls (3.5% exposed), 805 cases of cleft lip with or without cleft palate (5.8% exposed), and 439 cases of cleft palate alone (4.6% exposed). The odds of maternal occupational exposure to polycyclic aromatic hydrocarbons (any versus none) during pregnancy was increased for cleft lip with or without cleft palate cases as compared with controls (odds ratio, 1.69; 95% confidence interval, 1.18 to 2.40); the odds ratio was 1.47 (95% confidence interval 1.02 to 2.12) when adjusted for maternal education. There was a statistically significant adjusted exposure-response relationship for cleft lip with or without cleft palate (Ptrend = .02). Odd ratios for cleft palate alone were not statistically significant.
  
  
  CONCLUSIONS
  Maternal occupational exposure to polycyclic aromatic hydrocarbons was associated with increased risk of cleft lip with or without cleft palate in offspring.
authors.affiliation: Texas Center for Birth Defects Research and Prevention, Texas Department of State Health Services, PO Box 149347, MC 1964, Austin, TX 78714-9347, USA. peter.langlois@dshs.state.tx.us
authors.forename: Peter H
authors.initials: PH
authors.lastname: Langlois
authors.forename: Adrienne T
authors.initials: AT
authors.lastname: Hoyt
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Lupo
authors.forename: Christina C
authors.initials: CC
authors.lastname: Lawson
authors.forename: Martha A
authors.initials: MA
authors.lastname: Waters
authors.forename: Tania A
authors.initials: TA
authors.lastname: Desrosiers
authors.forename: Gary M
authors.initials: GM
authors.lastname: Shaw
authors.forename: Paul A
authors.initials: PA
authors.lastname: Romitti
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Lammer
mesh_terms: D016022:Case-Control Studies; D002972:Cleft Palate; D006801:Humans; D018811:Maternal Exposure; D016273:Occupational Exposure; D011084:Polycyclic Aromatic Hydrocarbons; D012307:Risk Factors
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons