Air pollution exposure during pregnancy and reduced birth size: a prospective birth cohort study in Valencia, Spain

• Main Authors: Llop Sabrina (Author), Iñiguez Carmen (Author), Estarlich Marisa (Author), Ballester Ferran (Author), Ramón Rosa (Author), Esplugues Ana (Author), Lacasaña Marina (Author), Rebagliato Marisa (Author)
• Format: Book
• Published: BMC, 2010-01-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.1186/1476-069X-9-6; 1476-069X
• Keywords: Industrial medicine. Industrial hygiene; RC963-969; Public aspects of medicine; RA1-1270
• Source: Environmental Health, Vol 9, Iss 1, p 6 (2010)

<p>Abstract</p> <p>Background</p> <p>Maternal exposure to air pollution has been related to fetal growth in a number of recent scientific studies. The objective of this study was to assess the association between exposure to air pollution during pregnancy and anthropometric measures at birth in a cohort in Valencia, Spain.</p> <p>Methods</p> <p>Seven hundred and eighty-five pregnant women and their singleton newborns participated in the study. Exposure to ambient nitrogen dioxide (NO₂) was estimated by means of land use regression. NO₂spatial estimations were adjusted to correspond to relevant pregnancy periods (whole pregnancy and trimesters) for each woman. Outcome variables were birth weight, length, and head circumference (HC), along with being small for gestational age (SGA). The association between exposure to residential outdoor NO₂and outcomes was assessed controlling for potential confounders and examining the shape of the relationship using generalized additive models (GAM).</p> <p>Results</p> <p>For continuous anthropometric measures, GAM indicated a change in slope at NO₂concentrations of around 40 μg/m³. NO₂exposure >40 μg/m³during the first trimester was associated with a change in birth length of -0.27 cm (95% CI: -0.51 to -0.03) and with a change in birth weight of -40.3 grams (-96.3 to 15.6); the same exposure throughout the whole pregnancy was associated with a change in birth HC of -0.17 cm (-0.34 to -0.003). The shape of the relation was seen to be roughly linear for the risk of being SGA. A 10 μg/m³increase in NO₂during the second trimester was associated with being SGA-weight, odds ratio (OR): 1.37 (1.01-1.85). For SGA-length the estimate for the same comparison was OR: 1.42 (0.89-2.25).</p> <p>Conclusions</p> <p>Prenatal exposure to traffic-related air pollution may reduce fetal growth. Findings from this study provide further evidence of the need for developing strategies to reduce air pollution in order to prevent risks to fetal health and development.</p>