title: Associations between prenatal traffic-related air pollution exposure and birth weight: Modification by sex and maternal pre-pregnancy body mass index.
abstract: Prenatal traffic-related air pollution exposure is linked to adverse birth outcomes. However, modifying effects of maternal body mass index (BMI) and infant sex remain virtually unexplored.
  
  
  
  We examined whether associations between prenatal air pollution and birth weight differed by sex and maternal BMI in 670 urban ethnically mixed mother-child pairs.
  
  
  
  Black carbon (BC) levels were estimated using a validated spatio-temporal land-use regression (LUR) model; fine particulate matter (PM2.5) was estimated using a hybrid LUR model incorporating satellite-derived Aerosol Optical Depth measures. Using stratified multivariable-adjusted regression analyses, we examined whether associations between prenatal air pollution and calculated birth weight for gestational age (BWGA) z-scores varied by sex and maternal pre-pregnancy BMI.
  
  
  
  Median birth weight was 3.3±0.6kg; 33% of mothers were obese (BMI ≥30kg/m(3)). In stratified analyses, the association between higher PM2.5 and lower birth weight was significant in males of obese mothers (-0.42 unit of BWGA z-score change per IQR increase in PM2.5, 95%CI: -0.79 to -0.06) ( PM2.5×sex×obesity Pinteraction=0.02). Results were similar for BC models (Pinteraction=0.002).
  
  
  
  Associations of prenatal exposure to traffic-related air pollution and reduced birth weight were most evident in males born to obese mothers.
authors.affiliation: Division of Neonatal Medicine, Children's Hospital Los Angeles, Los Angeles, CA, USA.
authors.forename: Ashwini
authors.initials: A
authors.lastname: Lakshmanan
authors.affiliation: Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
authors.forename: Yueh-Hsiu Mathilda
authors.initials: YH
authors.lastname: Chiu
authors.affiliation: Department of Biostatistics, Harvard School of Public Health, Boston, MA, USA.|Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA.
authors.forename: Brent A
authors.initials: BA
authors.lastname: Coull
authors.affiliation: Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA.
authors.forename: Allan C
authors.initials: AC
authors.lastname: Just
authors.affiliation: Channing Laboratory, Department of Medicine, Brigham and Women's Hospital & Harvard Medical School, Boston, MA.
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Maxwell
authors.affiliation: Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA.
authors.forename: Joel
authors.initials: J
authors.lastname: Schwartz
authors.affiliation: Department of Hygiene, Epidemiology and Medical Statistics, Medical School of Athens, Athens, Greece.
authors.forename: Alexandros
authors.initials: A
authors.lastname: Gryparis
authors.affiliation: Department of Geography and Environmental Development, Ben-Gurion University of the Negev, Beersheba, Israel.
authors.forename: Itai
authors.initials: I
authors.lastname: Kloog
authors.affiliation: Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA.|The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
authors.forename: Rosalind J
authors.initials: RJ
authors.lastname: Wright
authors.affiliation: Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA.|The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
authors.forename: Robert O
authors.initials: RO
authors.lastname: Wright
mesh_terms: D000293:Adolescent; D000328:Adult; D000393:Air Pollutants / Q000032:analysis*; D001724:Birth Weight / Q000187:drug effects*; D015992:Body Mass Index; D001900:Boston / Q000453:epidemiology; D004784:Environmental Monitoring; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D018811:Maternal Exposure; D015999:Multivariate Analysis; D052638:Particulate Matter / Q000032:analysis; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology*; D012727:Sex Characteristics; D053260:Soot / Q000032:analysis; D001335:Vehicle Emissions / Q000032:analysis*; D055815:Young Adult
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D053260:Soot; D001335:Vehicle Emissions
keywords: Birth weight; Body mass index; Prenatal exposure; Sex; Traffic-related air pollution