title: Fetal growth and air pollution - A study on ultrasound and birth measures.
abstract: Air pollution has been suggested to affect fetal growth, but more data is needed to assess the timing of exposure effects by using ultrasound measures. It is also important to study effects in low exposure areas to assess eventual thresholds of effects. The MAPSS (Maternal Air Pollution in Southern Sweden) cohort consists of linked registry data for around 48,000 pregnancies from an ultrasound database, birth registry and exposure data based on residential addresses. Measures of air pollution exposure were obtained through dispersion modelling with input data from an emissions database (NOx) with high resolution (100-500m grids). Air pollution effects were assessed with linear regressions for the following endpoints; biparietal diameter, femur length, abdominal diameter and estimated fetal weight measured in late pregnancy and birth weight and head circumference measured at birth. We estimated negative effects for NOx; in the adjusted analyses the decrease of abdominal diameter and femur length were -0.10 (-0.17, -0.03) and -0.13 (-0.17, -0.01)mm, respectively, per 10µg/m3increment of NOx. We also estimated an effect of NOx-exposures on birth weight by reducing birth weight by 9g per 10µg/m3increment of NOx. We estimated small but statistically significant effects of air pollution on late fetal and birth size and reduced fetal growth late in pregnancy in a geographic area with levels below current WHO air quality guidelines.
authors.affiliation: Division of Occupational and Environmental Medicine, Lund University, Sweden. Electronic address: Ebba.malmqvist@med.lu.se.
authors.forename: Ebba
authors.initials: E
authors.lastname: Malmqvist
authors.affiliation: Department of Epidemiology, Fielding School of Public Health, University of California at Los Angeles, CA, USA.
authors.forename: Zeyan
authors.initials: Z
authors.lastname: Liew
authors.affiliation: Division of Occupational and Environmental Medicine, Lund University, Sweden.
authors.forename: Karin
authors.initials: K
authors.lastname: Källén
authors.affiliation: Division of Occupational and Environmental Medicine, Lund University, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Rignell-Hydbom
authors.affiliation: Division of Occupational and Environmental Medicine, Lund University, Sweden.
authors.forename: Ralf
authors.initials: R
authors.lastname: Rittner
authors.affiliation: Division of Occupational and Environmental Medicine, Lund University, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Rylander
authors.affiliation: Department of Epidemiology, Fielding School of Public Health, University of California at Los Angeles, CA, USA.
authors.forename: Beate
authors.initials: B
authors.lastname: Ritz
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D015415:Biomarkers / Q000032:analysis; D015331:Cohort Studies; D004781:Environmental Exposure; D004784:Environmental Monitoring; D005260:Female; D047109:Fetal Development; D005333:Fetus / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D018811:Maternal Exposure; D009589:Nitrogen Oxides / Q000032:analysis*; D011247:Pregnancy; D013548:Sweden; D014463:Ultrasonography; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D015415:Biomarkers; D009589:Nitrogen Oxides; D001335:Vehicle Emissions
keywords: Air pollution; Birth weight; Fetal growth; Nitrogen oxides; Ultrasound