The study, published in Environmental Health Perspectives, shows that prenatal exposure to air pollution is associated with fetal growth. The project, called INMA (Children and the Environment) and which has had the presence of researchers from the Center for Research in Environmental Epidemiology (CREAL), indicates that pollution from traffic influences the size of the fetus.
"The aim of this study was to investigate the impact of nitrogen dioxide (NO2) in fetal and neonatal biometrics in the Spanish INMA project ”, says the expert.
Until now, exposure to air pollution during pregnancy has been associated with delayed fetal growth. However, few studies to date have measured fetal biometry longitudinally, in order to verify areas of special vulnerability.
"The aim of this study was to investigate the impact of nitrogen dioxide (NO2) in fetal and neonatal biometrics in the Spanish INMA project ”, explains Mònica Guxens, CREAL researcher, participant in this study.
Measurements of the fetus in each trimester of pregnancy
In each trimester of pregnancy, the scientists evaluated the biparietal diameter (which is the distance between the two parietal bones of the fetal skull) in 2,478 fetuses, the length of the femur, the abdominal circumference, and the estimated fetal weight.
These measures, as well as anthropometry at birth, were evaluated using specific growth-cohort curves at 12, 20 and 34 weeks of gestation. To estimate exposure to NO2 In households throughout the pregnancy process, land use regression measures were used.
The researchers found that an increase of 10 µg / m3 at mean NO exposure2 During the first twelve weeks of pregnancy, it was associated with lower growth in this period in abdominal circumference and estimated fetal weight.
“The same exposure was inversely associated with lower growth between weeks 20 and 34 in biparietal diameter, abdominal circumference, and estimated fetal weight, but a less consistent pattern of association was observed in femur length growth. The negative association of this exposure with biparietal diameter and fetal weight was significantly higher in smokers compared with nonsmoking mothers, ”Guxens emphasizes.