title: Indoor air pollution and the risk of orofacial clefts in a rural population in Shanxi province, China.
abstract: BACKGROUND
  Shanxi Province is a region in China with a high incidence of orofacial clefts (OFCs). Our objective is to investigate the effect of maternal exposure to indoor air pollution (IAP) from coal combustion and tobacco smoke on the risk of an infant being born with orofacial clefts.
  
  
  METHODS
  Data were derived from an ongoing population-based case-control study of major external structural birth defects in Shanxi Province. Subjects included 213 cases with OFCs and 1319 healthy babies born between November 2002 and December 2014 in four rural counties. Exposure information was collected by face-to-face interview with mothers within 1 week of delivery or pregnancy termination. The authors derived an exposure index by integrating a series of IAP-related characteristics concerning dwelling and lifestyle.
  
  
  RESULTS
  Increased odds of OFC were associated with IAP exposure from heating (adjusted odds ratio [aOR] = 2.4; 95% confidence interval [CI], 1.2-4.5) and from smoking (aOR = 1.8; 95% CI: 1.3, 2.5), but not with exposure from cooking (aOR = 0.9; 95% CI, 0.6-1.4). Compared with women without IAP exposure, the aORs of OFC for children of women with exposure indices of 1, 2, 3 and ≥ 4 were 1.1 (95% CI, 0.6-1.8), 1.4 (95% CI, 0.8-2.4), 1.8 (95% CI, 1.0-3.2), and 3.4 (95% CI, 1.6-7.4), respectively, demonstrating a clear dose-response trend (p < 0.001).
  
  
  CONCLUSIONS
  Periconceptional exposure to IAP from coal combustion and tobacco smoking may increase the risk of OFCs in offsprings of women in Shanxi Province. Birth Defects Research (Part A) 106:708-715, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Institute of Reproductive and Child Health/Ministry of Health Key Laboratory of Reproductive Health, Peking University, China.|Department of Epidemiology and Biostatistics, School of Public Health, Peking University, China.
authors.forename: Yingying
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Institute of Reproductive and Child Health/Ministry of Health Key Laboratory of Reproductive Health, Peking University, China.|Department of Epidemiology and Biostatistics, School of Public Health, Peking University, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.affiliation: Institute of Reproductive and Child Health/Ministry of Health Key Laboratory of Reproductive Health, Peking University, China.|Department of Epidemiology and Biostatistics, School of Public Health, Peking University, China.
authors.forename: Zhiwen
authors.initials: Z
authors.lastname: Li
authors.affiliation: Institute of Reproductive and Child Health/Ministry of Health Key Laboratory of Reproductive Health, Peking University, China.|Department of Epidemiology and Biostatistics, School of Public Health, Peking University, China.
authors.forename: Le
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Institute of Reproductive and Child Health/Ministry of Health Key Laboratory of Reproductive Health, Peking University, China.|Department of Epidemiology and Biostatistics, School of Public Health, Peking University, China.
authors.forename: Jufen
authors.initials: J
authors.lastname: Liu
authors.affiliation: Institute of Reproductive and Child Health/Ministry of Health Key Laboratory of Reproductive Health, Peking University, China.|Department of Epidemiology and Biostatistics, School of Public Health, Peking University, China.
authors.forename: Aiguo
authors.initials: A
authors.lastname: Ren
mesh_terms: D000328:Adult; D016902:Air Pollution, Indoor / Q000009:adverse effects*; D016022:Case-Control Studies; D002648:Child; D002971:Cleft Lip / Q000175:diagnosis / Q000209:etiology* / Q000473:pathology; D002972:Cleft Palate / Q000175:diagnosis / Q000209:etiology* / Q000473:pathology; D003031:Coal / Q000009:adverse effects; D005260:Female; D006361:Heating / Q000009:adverse effects*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects*; D016017:Odds Ratio; D011247:Pregnancy; D012307:Risk Factors; D012424:Rural Population; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D003031:Coal; D014028:Tobacco Smoke Pollution
keywords: air pollution; coal; indoor; orofacial clefts; passive smoking