title: Prenatal air pollution exposure and ultrasound measures of fetal growth in Los Angeles, California.
abstract: BACKGROUND
  Few previous studies examined the impact of prenatal air pollution exposures on fetal development based on ultrasound measures during pregnancy.
  
  
  METHODS
  In a prospective birth cohort of more than 500 women followed during 1993-1996 in Los Angeles, California, we examined how air pollution impacts fetal growth during pregnancy. Exposure to traffic related air pollution was estimated using CALINE4 air dispersion modeling for nitrogen oxides (NOx) and a land use regression (LUR) model for nitrogen monoxide (NO), nitrogen dioxide (NO2) and NOx. Exposures to carbon monoxide (CO), NO2, ozone (O3) and particles <10μm in aerodynamic diameter (PM10) were estimated using government monitoring data. We employed a linear mixed effects model to estimate changes in fetal size at approximately 19, 29 and 37 weeks gestation based on ultrasound.
  
  
  RESULTS
  Exposure to traffic-derived air pollution during 29 to 37 weeks was negatively associated with biparietal diameter at 37 weeks gestation. For each interquartile range (IQR) increase in LUR-based estimates of NO, NO2 and NOx, or freeway CALINE4 NOx we estimated a reduction in biparietal diameter of 0.2-0.3mm. For women residing within 5km of a monitoring station, we estimated biparietal diameter reductions of 0.9-1.0mm per IQR increase in CO and NO2. Effect estimates were robust to adjustment for a number of potential confounders. We did not observe consistent patterns for other growth endpoints we examined.
  
  
  CONCLUSIONS
  Prenatal exposure to traffic-derived pollution was negatively associated with fetal head size measured as biparietal diameter in late pregnancy.
authors: Department of Epidemiology, Fielding School of Public Health, UCLA, 650 Charles E. Young Drive, Los Angeles, CA 90095-1772, USA; The David Geffen School of Medicine at UCLA, Los Angeles, CA, USA. Electronic address: britz@ucla.edu.
authors: Beate
authors: B
authors: Ritz
authors: Department of Biostatistics, Fielding School of Public Health, UCLA, Los Angeles, CA, USA.
authors: Jiaheng
authors: J
authors: Qiu
authors: Department of Epidemiology, Fielding School of Public Health, UCLA, 650 Charles E. Young Drive, Los Angeles, CA 90095-1772, USA.
authors: Pei-Chen
authors: PC
authors: Lee
authors: Sonoma Technology, Inc., Petaluma, CA, USA.
authors: Fred
authors: F
authors: Lurmann
authors: Sonoma Technology, Inc., Petaluma, CA, USA.
authors: Bryan
authors: B
authors: Penfold
authors: Department of Biostatistics, Fielding School of Public Health, UCLA, Los Angeles, CA, USA.
authors: Robert
authors: R
authors: Erin Weiss
authors: Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
authors: Rob
authors: R
authors: McConnell
authors: Department of Obstetrics, Gynecology and Pediatrics, Cedars Sinai Medical Center, Los Angeles, CA, USA; The David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
authors: Chander
authors: C
authors: Arora
authors: Department of Obstetrics, Gynecology and Pediatrics, Cedars Sinai Medical Center, Los Angeles, CA, USA; The David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
authors: Calvin
authors: C
authors: Hobel
authors: Department of Epidemiology, Fielding School of Public Health, UCLA, 650 Charles E. Young Drive, Los Angeles, CA 90095-1772, USA.
authors: Michelle
authors: M
authors: Wilhelm
mesh_terms: D000328:Adult; D000397:Air Pollution / Q000009:adverse effects*; D002248:Carbon Monoxide / Q000633:toxicity; D015331:Cohort Studies; D005260:Female; D047109:Fetal Development / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D015141:Los Angeles; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects*; D008962:Models, Theoretical; D009589:Nitrogen Oxides / Q000633:toxicity; D010126:Ozone / Q000633:toxicity; D052638:Particulate Matter / Q000633:toxicity; D011247:Pregnancy; D011446:Prospective Studies; D016216:Ultrasonography, Prenatal; D001335:Vehicle Emissions / Q000633:toxicity*; D055815:Young Adult
chemical_list: D009589:Nitrogen Oxides; D052638:Particulate Matter; D001335:Vehicle Emissions; D010126:Ozone; D002248:Carbon Monoxide
keywords: Ambient air pollution; Fetal growth; Pregnancy; Traffic-related air pollution; Ultrasound measurements