Background: Air pollution exposure during pregnancy has been associated with impaired fetal growth. However, few studies have measured fetal biometry longitudinally, remaining unclear as to whether there are windows of special vulnerability.
Objective: The aim was to investigate the impact of nitrogen dioxide (NO2) exposure on fetal and neonatal biometry in the Spanish INMA study.
Methods: Biparietal diameter (BPD), femur length (FL), abdominal circumference (AC), and estimated fetal weight (EFW) were evaluated for up to 2,478 fetuses in each trimester of pregnancy. Size at 12, 20, and 34 weeks of gestation and growth between these points, as well as anthropometry at birth, were assessed by SD scores derived using cohort-specific growth curves. Temporally adjusted land-use regression was used to estimate exposure to NO2 at home addresses for up to 2,415 fetuses. Associations were investigated by linear regression in each cohort and subsequent meta-analysis.
Results: A 10-μg/m3 increase in average exposure to NO2 during weeks 0–12 was associated with reduced growth at weeks 0–12 in AC (–2.1%; 95% CI: –3.7, –0.6) and EFW (–1.6%; 95% CI: –3.0, –0.3). The same exposure was inversely associated with reduced growth at weeks 20–34 in BPD (–2.6%; 95% CI: –3.9, –1.2), AC (–1.8%; 95% CI: –3.3, –0.2), and EFW (–2.1%; 95% CI: –3.7, –0.2). A less consistent pattern of association was observed for FL. The negative association of this exposure with BPD and EFW was significantly stronger in smoking versus nonsmoking mothers.
Conclusions: Maternal exposure to NO2 in early pregnancy was associated with reduced fetal growth based on ultrasound measures of growth during pregnancy and measures of size at birth.
1Epidemiology and Environmental Health Joint Research Unit, FISABIO–Universitat Jaume I–Universitat de València, Valencia, Spain; 2Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain; 3Center for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; 4Hospital del Mar Research Institute (IMIM), Barcelona, Spain; 5Pompeu Fabra University, Barcelona, Spain; 6Public Health Division, Basque Government, Spain; 7Health Research Institute, Biodonostia, San Sebastián, Spain; 8University of Oviedo, Oviedo, Spain; 9Swiss Tropical and Public Health Institute, Basel, Switzerland; 10University of Basel, Basel, Switzerland; 11University of the Basque Country (UPV/EHU), Bizkaia, Spain; 12Department of Child and Adolescent Psychiatry/Psychology, Erasmus University Medical Centre–Sophia Children’s Hospital, Rotterdam, the Netherlands
Recommended Citation:
Carmen Iñiguez,1,2 Ana Esplugues,et al. Prenatal Exposure to NO2 and Ultrasound Measures of Fetal Growth in the Spanish INMA Cohort[J]. Environmental Health Perspectives,2016-01-01,Volume 124(Issue 2):235