title: The possible association between exposure to air pollution and the risk for congenital malformations.
abstract: BACKGROUND
  Over the last decade, there is growing evidence that exposure to air pollution may be associated with increased risk for congenital malformations.
  
  
  OBJECTIVE
  To evaluate the possible association between exposures to air pollution during pregnancy and congenital malformations among infants born following spontaneously conceived (SC) pregnancies and assisted reproductive technology (ART) pregnancies.
  
  
  METHODS
  This is an historical cohort study comprising 216,730 infants: 207,825 SC infants and 8905 ART conceived infants, during the periods 1997-2004. Air pollution data including sulfur dioxide (SO2), particulate matter <10 µm (PM10), nitrogen oxides (NOx) and ozone (O3) were obtained from air monitoring stations database for the study period. Using a geographic information system (GIS) and the Kriging procedure, exposure to air pollution during the first trimester and the entire pregnancy was assessed for each woman according to her residential location. Logistic regression models with generalized estimating equation (GEE) approach were used to evaluate the adjusted risk for congenital malformations.
  
  
  RESULTS
  In the study cohort increased concentrations of PM10 and NOx pollutants in the entire pregnancy were associated with slightly increased risk for congenital malformations: OR 1.06(95% CI, 1.01-1.11) for 10 µg/m(3) increase in PM10 and OR 1.03(95% CI, 1.01-1.04) for 10 ppb increase in NOx. Specific malformations were evident in the circulatory system (for PM10 and NOx exposure) and genital organs (for NOx exposure). SO2 and O3 pollutants were not significantly associated with increased risk for congenital malformations. In the ART group higher concentrations of SO2 and O3 in entire pregnancy were associated (although not significantly) with an increased risk for congenital malformations: OR 1.06(95% CI, 0.96-1.17) for 1 ppb increase in SO2 and OR 1.15(95% CI, 0.69-1.91) for 10 ppb increase in O3.
  
  
  CONCLUSIONS
  Exposure to higher levels of PM10 and NOx during pregnancy was associated with an increased risk for congenital malformations. Specific malformations were evident in the circulatory system and genital organs. Among ART pregnancies possible adverse association of SO2 and O3 exposure was also observed. Further studies are warranted, including more accurate exposure assessment and a larger sample size for ART pregnancies, in order to confirm these findings.
authors.affiliation: (a)Women and children׳s Health Research Unit, Gertner Institute for Epidemiology and Health Policy Research Ltd., Israel. Electronic address: dollyf@gertner.health.gov.il.
authors.forename: Adel
authors.initials: A
authors.lastname: Farhi
authors.affiliation: (a)Women and children׳s Health Research Unit, Gertner Institute for Epidemiology and Health Policy Research Ltd., Israel.
authors.forename: Valentina
authors.initials: V
authors.lastname: Boyko
authors.affiliation: (b)Department of Geography and Human Environment, Tel Aviv University, Israel.
authors.forename: Jonatan
authors.initials: J
authors.lastname: Almagor
authors.affiliation: (b)Department of Geography and Human Environment, Tel Aviv University, Israel.
authors.forename: Itzhak
authors.initials: I
authors.lastname: Benenson
authors.affiliation: (c)Department of Earth and Planetary Sciences, Weizmann Institute of Science, Israel.
authors.forename: Enrico
authors.initials: E
authors.lastname: Segre
authors.affiliation: (c)Department of Earth and Planetary Sciences, Weizmann Institute of Science, Israel.
authors.forename: Yinon
authors.initials: Y
authors.lastname: Rudich
authors.affiliation: (d)Center for Risk Analysis, Gertner Institute for Epidemiology and Health Policy Research Ltd., Israel.
authors.forename: Eli
authors.initials: E
authors.lastname: Stern
authors.affiliation: (e)School of public health, Sackler Faculty of Medicine, Tel Aviv University, Israel; (e)School of public health, Sackler Faculty of Medicine, Tel Aviv University, Israel.
authors.forename: Liat
authors.initials: L
authors.lastname: Lerner-Geva
mesh_terms: D000397:Air Pollution / Q000009:adverse effects*; D015331:Cohort Studies; D000013:Congenital Abnormalities / Q000209:etiology*; D005260:Female; D040362:Geographic Information Systems; D006801:Humans; D007557:Israel; D018811:Maternal Exposure / Q000009:adverse effects*; D009569:Nitric Oxide / Q000032:analysis; D016017:Odds Ratio; D010126:Ozone / Q000032:analysis; D052638:Particulate Matter / Q000032:analysis; D011247:Pregnancy; D027724:Reproductive Techniques, Assisted; D013458:Sulfur Dioxide / Q000032:analysis
chemical_list: D052638:Particulate Matter; D013458:Sulfur Dioxide; D009569:Nitric Oxide; D010126:Ozone
keywords: Air pollution; Assisted reproductive technology; Congenital malformations; Nitrogen oxides; Ozone; Particulate matter <10µm