title: Maternal ambient air pollution exposure preconception and during early gestation and offspring congenital orofacial defects.
abstract: BACKGROUND
  Maternal air pollution exposure has been related to orofacial clefts but the literature is equivocal. Potential chronic preconception effects have not been studied.
  
  
  OBJECTIVE
  Criteria air pollutant exposure during three months preconception and gestational weeks 3-8 was studied in relation to orofacial defects.
  
  
  METHODS
  Among 188,102 live births and fetal deaths from the Consortium on Safe Labor (2002-2008), 63 had isolated cleft palate (CP) and 159 had isolated cleft lip with or without cleft palate (CL ±CP). Exposures were estimated using a modified Community Multiscale Air Quality model. Logistic regression with generalized estimating equations adjusted for site/region and maternal demographic, lifestyle and clinical factors calculated the odds ratio (OR) and 95% CI per interquartile increase in each pollutant.
  
  
  RESULTS
  Preconception, carbon monoxide (CO; OR=2.24; CI: 1.21, 4.16) and particulate matter (PM) ≤10 µm (OR=1.72; CI: 1.12, 2.66) were significantly associated with CP, while sulfur dioxide (SO2) was associated with CL ±CP (OR=1.93; CI: 1.16, 3.21). During gestational weeks 3-8, CO remained a significant risk for CP (OR=2.74; CI: 1.62, 4.62) and nitrogen oxides (NOx; OR=3.64; CI: 1.73, 7.66) and PM ≤2.5 µm (PM2.5; OR=1.74; CI: 1.15, 2.64) were also related to the risk. Analyses by individual week revealed that positive associations of NOx and PM2.5 with CP were most prominent from weeks 3-6 and 3-5, respectively.
  
  
  CONCLUSIONS
  Exposure to several criteria air pollutants preconception and during early gestation was associated with elevated odds for CP, while CL ±CP was only associated with preconception SO2 exposure.
authors.affiliation: Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Rockville, MD, USA.
authors.forename: Yeyi
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Rockville, MD, USA.
authors.forename: Cuilin
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Biostatistics and Bioinformatics Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Rockville, MD, USA.
authors.forename: Danping
authors.initials: D
authors.lastname: Liu
authors.affiliation: Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Rockville, MD, USA.
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Grantz
authors.affiliation: Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Rockville, MD, USA.
authors.forename: Maeve
authors.initials: M
authors.lastname: Wallace
authors.affiliation: Epidemiology Branch, Division of Intramural Population Health Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Rockville, MD, USA. Electronic address: pauline.mendola@nih.gov.
authors.forename: Pauline
authors.initials: P
authors.lastname: Mendola
mesh_terms: D000328:Adult; D000397:Air Pollution; D000013:Congenital Abnormalities; D004781:Environmental Exposure; D005145:Face / Q000002:abnormalities*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy; D055815:Young Adult
keywords: Air pollution; Cleft lip; Cleft palate; Organogenesis; Preconception exposure